List of numbers

This is a list of articles about numbers (not about numerals).

1 Rational numbers
2 Irrational and suspected irrational numbers
3 Hypercomplex numbers
- 3.1 Algebraic complex numbers
- 3.2 Other hypercomplex numbers
4 Transfinite numbers
5 Numbers representing measured quantities
6 Numbers representing scientific quantities
7 Numbers without specific values
8 Bases
9 See also
10 Notes
11 Further reading
12 External links

Rational numbers

Natural numbers

	1	2	3	4	5	6	7	8	9
10	11	12	13	14	15	16	17	18	19
20	21	22	23	24	25	26	27	28	29
30	31	32	33	34	35	36	37	38	39
40	41	42	43	44	45	46	47	48	49
50	51	52	53	54	55	56	57	58	59
60	61	62	63	64	65	66	67	68	69
70	71	72	73	74	75	76	77	78	79
80	81	82	83	84	85	86	87	88	89
90	91	92	93	94	95	96	97	98	99
100	101	102	103	104	105	106	107	108	109
110	111	112	113	114	115	116	117	118	119
120	121	122	123	124	125	126	127	128	129
130	131	132	133	134	135	136	137	138	139
140	141	142	143	144	145	146	147	148	149
150	151	152	153	154	155	156	157	158	159
160	161	162	163	164	165	166	167	168	169
170	171	172	173	174	175	176	177	178	179
180	181	182	183	184	185	186	187	188	189
190	191	192	193	194	195	196	197	198	199
200	201	202	203	204	205	206	207	208	209
210	211	212	213	214	215	216
		220	230	240	250	260	270	280	290
			300	400	500	600	700	800	900
	1000	2000	3000	4000	5000	6000	7000	8000	9000
	10000	20000	30000	40000	50000	60000	70000	80000	90000
100k–1M		1M–10M		10M–100M		100M–1000M		Larger numbers

Powers of ten

Integers

Notable integers

Other numbers that are notable for their mathematical properties or cultural meanings include:

−40, an equal point in the Fahrenheit and Celsius scales.
−1
0, a number which quantifies a count or an amount of null size.
42, the Answer to the Ultimate Question of Life, the Universe, and Everything according to the Hitchhikers Guide to the Galaxy
255, 2⁸−1
496, a perfect number.
786, regarded as sacred by some Muslims although there is no such evidence in the Quran or Hadith.
911, the emergency phone number in the United States and Canada.
999, the emergency phone number in the United Kingdom.
1729, a taxicab number; the smallest number that can be written as the sum of two cubes in two different ways
142857, a base 10 cyclic number.
2147483647, 2³¹−1, the maximum number that a 32-bit signed integer can reach.
9814072356, the largest perfect power that contains no repeated digits

Named integers

Graham's number
Moser's number
Shannon number
Hardy-Ramanujan number
Skewes' number
Number of the Beast
Leviathan number
Kaprekar's constant

Prime numbers

A prime number is a positive integer which has exactly two divisors: one and itself.

The first 100 prime numbers:

2	3	5	7	11	13	17	19	23	29
31	37	41	43	47	53	59	61	67	71
73	79	83	89	97	101	103	107	109	113
127	131	137	139	149	151	157	163	167	173
179	181	191	193	197	199	211	223	227	229
233	239	241	251	257	263	269	271	277	281
283	293	307	311	313	317	331	337	347	349
353	359	367	373	379	383	389	397	401	409
419	421	431	433	439	443	449	457	461	463
467	479	487	491	499	503	509	521	523	541

Perfect numbers

A perfect number is an integer that is the sum of its positive proper divisors (all divisors except itself).

The first 10 perfect numbers:

1	6
2	28
3	496
4	8 128
5	33 550 336
6	8 589 869 056
7	137 438 691 328
8	2 305 843 008 139 952 128
9	2 658 455 991 569 831 744 654 692 615 953 842 176
10	191 561 942 608 236 107 294 793 378 084 303 638 130 997 321 548 169 216

Cardinal numbers

In the following tables, [and] indicates that the word and is used in some dialects (such as British English), and omitted in other dialects (such as American English).

Small numbers

This table demonstrates the standard English construction of small cardinal numbers up to ten million—names for which all variants of English agree.

Value	Name	Alternate names, and names for sets of the given size
0	Zero	aught, cipher, cypher, goose egg, love, nada, naught, nil, none, nought, nowt, null, ought, oh, squat, zed, zilch, zip
1	One	ace, single, singleton, unary, unit, unity
2	Two	binary, brace, couple, couplet, distich, deuce, double, doubleton, duad, duality, duet, duo, dyad, pair, snake eyes, span, twain, twosome, yoke
3	Three	deuce-ace, leash, set, tercet, ternary, ternion, terzetto, threesome, tierce, trey, triad, trine, trinity, trio, triplet, troika, hat-trick
4	Four	foursome, quadruplet, quatern, quaternary, quaternion, quaternity, quartet, tetrad
5	Five	cinque, fin, fivesome, pentad, quint, quintet, quintuplet
6	Six	half dozen, hexad, sestet, sextet, sextuplet, sise
7	Seven	heptad, septet, septuplet
8	Eight	octad, octave, octet, octonary, octuplet, ogdoad
9	Nine	ennead
10	Ten	deca, decade, sawbuck
11	Eleven	onze, ounze, ounce
12	Twelve	dozen
13	Thirteen	baker's dozen, long dozen
14	Fourteen
15	Fifteen
16	Sixteen
17	Seventeen
18	Eighteen
19	Nineteen
20	Twenty	score
21	Twenty-one
22	Twenty-two
23	Twenty-three
24	Twenty-four	two dozen
25	Twenty-five
26	Twenty-six
27	Twenty-seven
28	Twenty-eight
29	Twenty-nine
30	Thirty
31	Thirty-one
40	Forty
50	Fifty	half-century
60	Sixty	shock
70	Seventy	three-score and ten
80	Eighty	four-score
87	Eighty-seven	four-score and seven
90	Ninety
100	One hundred	centred, century, ton, short hundred
101	One hundred [and] one
110	One hundred [and] ten
111	One hundred [and] eleven,
120	One hundred [and] twenty	long hundred, great hundred, (obsolete) hundred
121	One hundred [and] twenty-one
144	One hundred [and] forty-four	gross, dozen dozen, small gross
200	Two hundred
300	Three hundred
666	Six Hundred [and] sixty-six	Number of the Beast
1 000	One thousand	chiliad, grand (or G), thou, yard, kilo (often shortened to k)
1 001	One thousand [and] one
1 010	One thousand [and] ten
1 011	One thousand [and] eleven
1 024	One thousand [and] twenty-four	kibi or kilo in computing, see binary prefix (kilo is shortened to k, Kibi to Ki)
1 100	One thousand one hundred
1 101	One thousand one hundred [and] one
1 728	One thousand seven hundred [and] twenty-eight	great gross, long gross, dozen gross
2 000	Two thousand
10 000	Ten thousand	myriad
100 000	One hundred thousand	lakh
500 000	Five hundred thousand	crore (Iranian)
1 000 000	One million	Mega, meg, mil, (often shortened to M)
1 048 576	One million forty-eight thousand five hundred [and] seventy-six	Mibi or Mega in computing, see binary prefix (Mega is shortened to M, Mibi to Mi)
10 000 000	Ten million	crore (Indian)

English names for powers of 10

This table compares the English names of cardinal numbers according to various American, British, and Continental European conventions. See names of numbers in English or English-language numerals for more information on naming numbers.

	Short scale	Long scale		Power
Value	American	British (Nicolas Chuquet)	Continental European (Jacques Peletier du Mans)	of a thousand	of a million
10⁰	One			1000^-1+1	1000000⁰
10¹	Ten
10²	Hundred
10³	Thousand			1000⁰⁺¹	1000000^0.5
10⁶	Million			1000¹⁺¹	1000000¹
10⁹	Billion	Thousand million	Milliard	1000²⁺¹	1000000^1.5
10¹²	Trillion	Billion		1000³⁺¹	1000000²
10¹⁵	Quadrillion	Thousand billion	Billiard	1000⁴⁺¹	1000000^2.5
10¹⁸	Quintillion	Trillion		1000⁵⁺¹	1000000³
10²¹	Sextillion	Thousand trillion	Trilliard	1000⁶⁺¹	1000000^3.5
10²⁴	Septillion	Quadrillion		1000⁷⁺¹	1000000⁴
10²⁷	Octillion	Thousand quadrillion	Quadrilliard	1000⁸⁺¹	1000000^4.5
10³⁰	Nonillion	Quintillion		1000⁹⁺¹	1000000⁵
10³³	Decillion	Thousand quintillion	Quintilliard	1000¹⁰⁺¹	1000000^5.5
10³⁶	Undecillion	Sextillion		1000¹¹⁺¹	1000000⁶
10³⁹	Duodecillion	Thousand sextillion	Sextilliard	1000¹²⁺¹	1000000^6.5
10⁴²	Tredecillion	Septillion		1000¹³⁺¹	1000000⁷
10⁴⁵	Quattuordecillion	Thousand septillion	Septilliard	1000¹⁴⁺¹	1000000^7.5
10⁴⁸	Quindecillion	Octillion		1000¹⁵⁺¹	1000000⁸
10⁵¹	Sexdecillion	Thousand octillion	Octilliard	1000¹⁶⁺¹	1000000^8.5
10⁵⁴	Septendecillion	Nonillion		1000¹⁷⁺¹	1000000⁹
10⁵⁷	Octodecillion	Thousand nonillion	Nonilliard	1000¹⁸⁺¹	1000000^9.5
10⁶⁰	Novemdecillion	Decillion		1000¹⁹⁺¹	1000000¹⁰
10⁶³	Vigintillion	Thousand decillion	Decilliard	1000²⁰⁺¹	1000000^10.5
10⁶⁶	Unvigintillion	Undecillion		1000²¹⁺¹	1000000¹¹
10⁶⁹	Duovigintillion	Thousand undecillion	Undecilliard	1000²²⁺¹	1000000^11.5
10⁷²	Trevigintillion	Duodecillion		1000²³⁺¹	1000000¹²
10⁷⁵	Quattuorvigintillion	...	...	1000²⁴⁺¹	1000000^12.5
...	...	...		...	...
10⁹³	Trigintillion	Thousand quindecillion	Quindecilliard	1000³⁰⁺¹	1000000^15.5
...	...	...		...	...
10¹²⁰	Novemtrigintillion	Vigintillion		1000³⁹⁺¹	1000000²⁰
10¹²³	Quadragintillion	Thousand vigintillion	Vigintilliard	1000⁴⁰⁺¹	1000000^20.5
...	...	...		...	...
10¹⁵³	Quinquagintillion	Thousand quinvigintillion	Quinvigintilliard	1000⁵⁰⁺¹	1000000^25.5
...	...	...		...	...
10¹⁸⁰	Novemquinquagintillion	Trigintillion		1000⁵⁹⁺¹	1000000³⁰
10¹⁸³	Sexagintillion	Thousand trigintillion	Trigintilliard	1000⁶⁰⁺¹	1000000^30.5
...	...	...		...	...
10²¹³	Septuagintillion	Thousand quintrigintillion	Quintrigintilliard	1000⁷⁰⁺¹	1000000^35.5
...	...	...		...	...
10²⁴⁰	Novemseptuagintillion	Quadragintillion		1000⁷⁹⁺¹	1000000⁴⁰
10²⁴³	Octogintillion	Thousand quadragintillion	Quadragintilliard	1000⁸⁰⁺¹	1000000^40.5
...	...	...		...	...
10²⁷³	Nonagintillion	Thousand quinquadragintillion	Quinquadragintilliard	1000⁹⁰⁺¹	1000000^45.5
...	...	...		...	...
10³⁰⁰	Novemnonagintillion	Quinquagintillion		1000⁹⁹⁺¹	1000000⁵⁰
10³⁰³	Centillion	Thousand quinquagintillion	Quinquagintilliard	1000¹⁰⁰⁺¹	1000000^50.5
...		...		...	...
10³⁶⁰		Sexagintillion		1000¹¹⁹⁺¹	1000000⁶⁰
10⁴²⁰		Septuagintillion		1000¹³⁹⁺¹	1000000⁷⁰
10⁴⁸⁰		Octogintillion		1000¹⁵⁹⁺¹	1000000⁸⁰
10⁵⁴⁰		Nonagintillion		1000¹⁷⁹⁺¹	1000000⁹⁰
10⁶⁰⁰		Centillion		1000¹⁹⁹⁺¹	1000000¹⁰⁰
10⁶⁰³	Ducentillion	Thousand Centillion	Centilliard	1000²⁰⁰⁺¹	1000000^100.5

There is no consistent and widely accepted way to extend cardinals beyond centillion (centilliard).

Proposed systematic names for powers of 10

Gillion system

In 2001, Russ Rowlett, Director of the Center for Mathematics and Science Education at the University of North Carolina at Chapel Hill proposed that, to avoid confusion, the Latin based short scale and long scale systems should be replaced by an unambiguous system using Greek-derived numerical prefixes for naming large numbers that would be based on powers of one thousand: ^[1]

Value	Name
10³	Thousand
10⁶	Million
10⁹	Gillion
10¹²	Tetrillion
10¹⁵	Pentillion
10¹⁸	Hexillion
10²¹	Heptillion
10²⁴	Oktillion
10²⁷	Ennillion
10³⁰	Dekillion

Value	Name
10³³	Hendekillion
10³⁶	Dodekillion
10³⁹	Trisdekillion
10⁴²	Tetradekillion
10⁴⁵	Pentadekillion
10⁴⁸	Hexadekillion
10⁵¹	Heptadekillion
10⁵⁴	Oktadekillion
10⁵⁷	Enneadekillion
10⁶⁰	Icosillion

Value	Name
10⁶³	Icosihenillion
10⁶⁶	Icosidillion
10⁶⁹	Icositrillion
10⁷²	Icositetrillion
10⁷⁵	Icosipentillion
10⁷⁸	Icosihexillion
10⁸¹	Icosiheptillion
10⁸⁴	Icosioktillion
10⁸⁷	Icosiennillion
10⁹⁰	Triacontillion

Myriad system

Proposed by Donald E. Knuth:

Value	Name	Notation
10⁰	One	1
10¹	Ten	10
10²	Hundred	100
10³	Ten hundred	1000
10⁴	Myriad	1,0000
10⁵	Ten myriad	10,0000
10⁶	Hundred myriad	100,0000
10⁷	Ten hundred myriad	1000,0000
10⁸	Myllion	1;0000,0000
10¹²	Myriad myllion	1,0000;0000,0000
10¹⁶	Byllion	1:0000,0000;0000,0000
10²⁴	Myllion byllion	1;0000,0000:0000,0000;0000,0000
10³²	Tryllion	1'0000,0000;0000,0000:0000,0000;0000,0000
10⁶⁴	Quadryllion	1'0000,0000;0000,0000:0000,0000;0000,0000'0000,0000;0000,0000:0000,0000;0000,0000
10¹²⁸	Quintyllion	1'0000,0000;0000,0000:0000,0000;0000,0000'0000,0000;0000,0000:0000,0000;0000,0000'0000,0000;0000,0000:0000,0000;0000,0000'0000,0000;0000,0000:0000,0000;0000,0000
10²⁵⁶	Sextyllion	1'0000,0000;0000,0000:0000,0000;0000,0000'0000,0000;0000,0000:0000,0000;0000,0000'0000,0000;0000,0000:0000,0000;0000,0000'0000,0000;0000,0000:0000,0000;0000,0000'0000,0000;0000,0000:0000,0000;0000,0000'0000,0000;0000,0000:0000,0000;0000,0000'0000,0000;0000,0000:0000,0000;0000,0000'0000,0000;0000,0000:0000,0000;0000,0000
10⁵¹²	Septyllion
10¹⁰²⁴	Octyllion
10²⁰⁴⁸	Nonyllion
10⁴⁰⁹⁶	Decyllion
10⁸¹⁹²	Undecyllion
10^16,384	Duodecyllion
10^32,768	Tredecyllion
10^65,536	Quattuordecyllion
10^131,072	Quindecyllion
10^262,144	Sexdecyllion
10^524,288	Septendecyllion
10^1,048,576	Octodecyllion
10^2,097,152	Novemdecyllion
10^4,194,304	Vigintyllion
10^8,388,608	Cafarolion
10^16,777,216	Saralion
${10}^{\,\! 4 \cdot 2^{40}}$	Quadragintyllion
${10}^{\,\! 4 \cdot 2^{50}}$	Quinquagintyllion
${10}^{\,\! 4 \cdot 2^{60}}$	Sexagintyllion
${10}^{\,\! 4 \cdot 2^{70}}$	Septuagintyllion
${10}^{\,\! 4 \cdot 2^{80}}$	Octogintyllion
${10}^{\,\! 4 \cdot 2^{90}}$	Nonagintyllion
${10}^{\,\! 4 \cdot 2^{100}}$	Centyllion
${10}^{\,\! 4 \cdot 2^{1000}}$	Millyllion
${10}^{\,\! 4 \cdot 2^{10000}}$	Myryllion

Googol and others

10¹⁰⁰	Googol
10^10¹⁰⁰	Googolplex
10^-N	N-minex
10^N	N-plex

SI-derived

Value	SI prefix	Name	Binary prefix	Value
1 000	k	Kilo (k)	Ki	1024
1 000 000	M	Mega (M)	Mi	1 048 576
1 000 000 000	G	Giga	Gi	1 073 741 824

Fractional numbers

This is a table of English names for positive rational numbers less than or equal to 1. It also lists alternative names, but there is no widespread convention for the names of extremely small positive numbers.

Keep in mind that rational numbers like 0.12 can be represented in infinitely many ways, e.g. zero-point-one-two (0.12), twelve percent (12%), three twenty-fifths $\left({3 \over 25}\right)$ , nine seventy-fifths $\left({9 \over 75} \right)$ , six fiftieths $\left({6 \over 50}\right)$ , twelve hundredths $\left({12 \over 100}\right)$ , twenty-four two-hundredths $\left({24 \over 200}\right)$ , etc.

Value	Fraction	Common names	Alternative names
1	$1 \over 1$	One	0.999...
0.9	$9 \over 10$	Nine tenths, [zero] point nine
0.8	$4 \over 5$	Four fifths, eight tenths, [zero] point eight
0.7	$7 \over 10$	Seven tenths, [zero] point seven
0.6	$3 \over 5$	Three fifths, six tenths, [zero] point six
0.5	$1 \over 2$	One half, five tenths, [zero] point five
0.4	$2 \over 5$	Two fifths, four tenths, [zero] point four
0.3 (333 333)...	$1 \over 3$	One third
0.3	$3 \over 10$	Three tenths, [zero] point three
0.25	$1 \over 4$	One quarter, one fourth, twenty-five hundredths, [zero] point two five
0.2	$1 \over 5$	One fifth, two tenths, [zero] point two
0.16 (666 666)...	$1 \over 6$	One sixth
0.142 857 (142 857)...	$1 \over 7$	One seventh
0.125	$1 \over 8$	One eighth, one-hundred-[and-]twenty-five thousandths, [zero] point one two five
0.1 (111 111)...	$1 \over 9$	One ninth
0.1	$1 \over 10$	One tenth, [zero] point one	One perdecime, one perdime
0.090 (909 090)...	$1 \over 11$	One eleventh
0.09	$9 \over 100$	Nine hundredths, [zero] point zero nine
0.083 (333 333)...	$1 \over 12$	One twelfth
0.08	$2 \over 25$	Two twenty-fifths, eight hundredths, [zero] point zero eight
0.0625	$1 \over 16$	One sixteenth, six-hundred-[and-]twenty-five ten-thousandths, [zero] point zero six two five
0.05	$1 \over 20$	One twentieth, [zero] point zero five
0.047 619 (047 619)...	$1 \over 21$	One twenty-first
0.045 (454 545)...	$1 \over 22$	One twenty-second
0.043 478 260 869 565 217 3913 (043 478)...	$1 \over 23$	One twenty-third
0.03 (333 333)...	$1 \over 30$	One thirtieth
0.016 (666 666)...	$1 \over 60$	One sixtieth	One minute
0.012345679 (012345679)...	$1 \over 81$	One eighty-first
0.01	$1 \over 100$	One hundredth, [zero] point zero one	One percent
0.001	$1 \over 1000$	One thousandth, [zero] point zero zero one	One permille
0.000 27 (777 777)...	$1 \over 3600$	One thirty-six hundredth	One second
0.000 1	$1 \over 10000$	One ten-thousandth, [zero] point zero zero zero one	One myriadth, one permyria, one permyriad, one basis point
0.000 01	$1 \over 10^5$	One hundred-thousandth	One lakhth, one perlakh
0.000 001	$1 \over 10^6$	One millionth	One perion, one ppm
0.000 000 1	$1 \over 10^7$	One ten-millionth	One crorth, one percrore
0.000 000 01	$1 \over 10^8$	One hundred-millionth	One awkth, one perawk
0.000 000 001	$1 \over 10^9$	One billionth (in some dialects)	One ppb
0	$0 \over 1$	Zero

Irrational and suspected irrational numbers

Algebraic numbers

Expression	Approximate value	Notes
${\sqrt{5} - 1} \over 2$	0.618 033 988 749 894 848 204 586 834 366	Golden ratio conjugate $\Phi\,$ , reciprocal of and one less than the golden ratio.
$\sqrt[12]{2}$	1.059 463 094 359 295 264 561 825 294 946	Twelfth root of two. Proportion between the frequencies of adjacent semitones in the equal temperament scale.
$\sqrt[3]{2}$	1.259 921 049 894 873 164 767 210 607 278	Cube root of two. Length of the edge of a cube with volume two. See doubling the cube for the significance of this number.
n/a	1.303 577 269 034 296 391 257 099 112 153	Conway's constant, defined as the unique positive real root of a certain polynomial of degree 71.
$\sqrt[3]{\frac{1}{2}+\frac{1}{6}\sqrt{\frac{23}{3}}}+$ $\sqrt[3]{\frac{1}{2}-\frac{1}{6}\sqrt{\frac{23}{3}}}$	1.324 717 957 244 746 025 960 908 854 478	Plastic number, the unique real root of the cubic equation $x^3=x+1\, .$
$\sqrt{2}$	1.414 213 562 373 095 048 801 688 724 210	$\sqrt{2} = 2 \sin 45^\circ = 2 \cos 45^\circ$ Square root of two a.k.a. Pythagoras' constant. Ratio of diagonal to side length in a square. Proportion between the sides of paper sizes in the ISO 216 series (originally DIN 476 series).
${\sqrt{5} + 1} \over 2$	1.618 033 988 749 894 848 204 586 834 366	Golden ratio $\left(\phi\right)$ , the larger of the two real roots of $x^2=x+1\, .$
$\sqrt{3}$	1.732 050 807 568 877 293 527 446 341 506	$\sqrt{3} = 2 \sin 60^\circ = 2 \cos 30^\circ$ Square root of three a.k.a. the measure of the fish. Length of the space diagonal of a cube with edge length 1. Length of the diagonal of a $1 \times \sqrt{2}$ rectangle. Altitude of an equilateral triangle with side length 2. Twice the altitude of an equilateral triangle with side length 1. Altitude of a regular hexagon with side length 1 and diagonal length 2.
$\sqrt{5}$	2.236 067 977 499 789 696 409 173 668 731	Square root of five. Length of the diagonal of a $1 \times 2$ rectangle. Length of the diagonal of a $\sqrt{2} \times \sqrt{3}$ rectangle. Length of the space diagonal of a $1 \times \sqrt{2} \times \sqrt{2}$ rectangular box.
$\sqrt{2} + 1$	2.414 213 562 373 095 048 801 688 724 210	Silver ratio $\left(\delta_S\right)$ , the larger of the two real roots of $x^2=2x+1\, .$
$\sqrt{6}$	2.449 489 742 783 178 098 197 284 074 706	$\sqrt{2} \cdot \sqrt{3}$ = area of a $\sqrt{2} \times \sqrt{3}$ rectangle. Length of the space diagonal of a $1 \times 1 \times 2$ rectangular box. Length of the diagonal of a $1 \times \sqrt{5}$ rectangle. Length of the diagonal of a $2 \times \sqrt{2}$ rectangle. Length of the diagonal of a square with side length $\sqrt{3}$ .
$\sqrt{7}$	2.645 751 311 064 590 590 501 615 753 639	Length of the space diagonal of a $1 \times 2 \times \sqrt{2}$ rectangular box. Length of the diagonal of a $1 \times \sqrt{6}$ rectangle. Length of the diagonal of a $2 \times \sqrt{3}$ rectangle. Length of the diagonal of a $\sqrt{2} \times \sqrt{5}$ rectangle.
$\sqrt{8}$	2.828 427 124 746 190 097 603 377 448 419	$2 \sqrt{2}$ Volume of a cube with edge length $\sqrt{2}$ . Length of the diagonal of a square with side length 2. Length of the diagonal of a $1 \times \sqrt{7}$ rectangle. Length of the diagonal of a $\sqrt{2} \times \sqrt{6}$ rectangle. Length of the diagonal of a $\sqrt{3} \times \sqrt{5}$ rectangle.
$\sqrt{10}$	3.162 277 660 168 379 331 998 893 544 433	$\sqrt{2} \cdot \sqrt{5}$ = area of a $\sqrt{2} \times \sqrt{5}$ rectangle. Length of the diagonal of a $1 \times 3$ rectangle. Length of the diagonal of a $2 \times \sqrt{6}$ rectangle. Length of the diagonal of a $\sqrt{3} \times \sqrt{7}$ rectangle. Length of the diagonal of a square with side length $\sqrt{5}$ .
$\sqrt{11}$	3.316 624 790 355 399 849 114 932 736 671	Length of the space diagonal of a $1 \times 1 \times 3$ rectangular box. Length of the diagonal of a $1 \times \sqrt{10}$ rectangle. Length of the diagonal of a $2 \times \sqrt{7}$ rectangle. Length of the diagonal of a $3 \times \sqrt{2}$ rectangle. Length of the diagonal of a $\sqrt{3} \times \sqrt{8}$ rectangle. Length of the diagonal of a $\sqrt{5} \times \sqrt{6}$ rectangle.
$\sqrt{12}$	3.464 101 615 137 754 587 054 892 683 012	$2 \sqrt{3}$ Length of the space diagonal of a cube with edge length 2. Length of the diagonal of a $1 \times \sqrt{11}$ rectangle. Length of the diagonal of a $2 \times \sqrt{8}$ rectangle. Length of the diagonal of a $3 \times \sqrt{3}$ rectangle. Length of the diagonal of a $\sqrt{2} \times \sqrt{10}$ rectangle. Length of the diagonal of a $\sqrt{5} \times \sqrt{7}$ rectangle. Length of the diagonal of a square with side length $\sqrt{6}$ .

Transcendental numbers

Liouville constant: c = 0.110001000000000000000001000...
Champernowne constant: C₁₀ = 0.12345678910111213141516...
iⁱ: 0.207879576...
Copeland–Erdős constant: 0.235711131719232931374143...
Prouhet–Thue–Morse constant: τ = 0.412454033640...
Cahen's constant: c = 0.64341054629...
Gauss's constant: G = 0.8346268...
Khinchin–Lévy constant: 1.1865691104...[1]
Favard constant: K₁ = 1.57079633...
log₂ 3: 1.584962501..., in fact, the logarithm of any positive integer to any integer base greater than one is either rational or transcendental.
√2^√2: 1.6325269...
Komornik–Loreti constant: q = 1.787231650...
Parabolic constant: P₂ = 2.29558714939...
Gelfond–Schneider constant: 2.665144143...
Euler's number: e = 2.718281828459045235360287471353...
Pi: π = 3.141592653589793238462643383279...
Tau: τ = 6.283185307179586...
Gelfond's constant: 23.14069263277925...
Ramanujan's constant: e^(π√163) = 262537412640768743.99999999999925...

Suspected transcendentals

Heath-Brown–Moroz constant: C = 0.001317641...
Kepler–Bouwkamp constant: 0.1149420448...
MRB constant: 0.187859...
Meissel–Mertens constant: M = 0.2614972128476427837554268386086958590516...
Bernstein's constant: β = 0.2801694990...
Strongly carefree constant: 0.286747...
Gauss–Kuzmin–Wirsing constant: λ₁ = 0.3036630029...[2]
Hafner–Sarnak–McCurley constant: 0.3532363719...
Artin's constant: 0.3739558136...
Prime constant: ρ = 0.414682509851111660248109622...
Carefree constant: 0.428249...
Omega constant: Ω = 0.5671432904097838729999686622...
Stephens' constant: 0.575959...
Euler–Mascheroni constant: γ = 0.577215664901532860606512090082...
Golomb–Dickman constant: λ = 0.62432998854355087099293638310083724...
Twin prime constant: C₂ = 0.660161815846869573927812110014...
Feller-Tornier constant: 0.661317...
Laplace limit: ε = 0.6627434193...[3]
Taniguchi's constant: 0.678234...
ln 2: 0.693147180559945309417232121458...
Embree–Trefethen constant: β* = 0.70258...
Sarnak's constant: 0.723648...
Landau–Ramanujan constant: 0.76422365358922066299069873125...
Brun's constant for prime quadruplets: B₂ = 0.8705883800...
Quadratic class number constant: 0.881513...
Catalan's constant: G = 0.915965594177219015054603514932384110774...
Viswanath's constant: σ(1) = 1.13198824...
Apéry's constant: ζ(3) = 1.202056903159594285399738161511449990764986292...
Vardi's constant: E = 1.264084735305...
Glaisher–Kinkelin constant: A = 1.28242712...
Mills' constant: A = 1.30637788386308069046...
Totient summatory constant: 1.339784...
Ramanujan–Soldner constant: μ = 1.451369234883381050283968485892027449493…
Backhouse's constant: 1.456074948...
Lieb's square ice constant: 1.5396007...
√2_s: 1.559610469...
Erdős–Borwein constant: E = 1.606695152415291763...
Somos' quadratic recurrence constant: σ = 1.661687949633594121296...
Niven's constant: c = 1.705211...
Brun's constant: B₂ = 1.902160583104...
Landau's totient constant: 1.943596...
Feigenbaum constant: α = 2.5029...
Sierpiński's constant: K = 2.5849817595792532170658936...
Barban's constant: 2.596536...
Khinchin's constant: K₀ = 2.685452001...[4]
Fransén–Robinson constant: F = 2.8077702420...
Murata's constant: 2.826419...
Lévy's constant: γ = 3.275822918721811159787681882...
Reciprocal Fibonacci constant: ψ = 3.359885666243177553172011302918927179688905133731...
Feigenbaum constant: δ = 4.6692...

Numbers not known with high precision

Landau's constant: 0.4330 < B < 0.472
Landau's constant: 0.5 < L < 0.544
Landau's constant: 0.5 < A < 0.7853
Grothendieck constant: 1.67 < k < 1.79

Hypercomplex numbers

Algebraic complex numbers

Imaginary unit: $i = \sqrt{-1}$
nth roots of unity: $\xi^k_n = \cos\left(2\pi \tfrac{k}{n}\right)+i\sin\left(2\pi \tfrac{k}{n}\right)$

Other hypercomplex numbers

The quaternions
The octonions
The sedenions
The dual numbers (with an infinitesimal)

Transfinite numbers

Infinity in general: $\infty$
Aleph-null: $\aleph_0$
Aleph-one: $\aleph_1$
Beth-one: ( $\beth_1$ ) is the cardinality of the continuum: $2^{\aleph_0}$

Numbers representing measured quantities

Pair: 2 (the base of the binary numeral system)
Dozen: 12 (the base of the duodecimal numeral system)
Baker's dozen: 13
Score: 20 (the base of the vigesimal numeral system)
Gross: 144 (= 12²)
Great gross: 1728 (= 12³)

Numbers representing scientific quantities

Planck constant: h = 6.6260689633... × 10^–34 Js
Electronvolt: eV = 1.60217648740... × 10^–19 J
Electron relative atomic mass: A_r(e) = 0.0005485799094323...
Molar mass constant: M_u = 0.001 kg/mol
Fine structure constant: α = 0.007297352537650...
Rydberg constant: R_∞ = 10973731.56852773... m⁻¹
Speed of light in vacuum: c = 299792458 m/s
Avogadro constant: N_A = 6.0221417930... × 10²³ mol⁻¹

Numbers without specific values

Bases

Base −10 (negadecimal)
Base −3 (negaternary)
Base −2 (negabinary)
Base 1 (unary)
Base 2 (binary)
Base 3 (ternary or trinary, see also balanced ternary)
Base 4 (quaternary)
Base 5 (quinary)
Base 6 (senary or heximal)
Base 7 (septenary)
Base 8 (octal)
Base 9 (nonary)
Base 10 (decimal)
Base 11 (undecimal)
Base 12 (duodecimal or dozenal)
Base 13 (tridecimal or tredecimal)
Base 14 (tetradecimal)
Base 15 (pentadecimal)
Base 16 (hexadecimal)
Base 20 (vigesimal)
Base 24 (quadrovigesimal)
Base 26 (hexavigesimal)
Base 27 (septemvigesimal)
Base 30 (trigesimal)
Base 32 (duotrigesimal)
Base 36 (hexatridecimal, sexatrigesimal or hexatrigesimal)
Base 60 (sexagesimal)
Mixed radix
Non-integer base (base φ, base plastic number, base e, base π, base √2)
Complex base (base 2i, base −1±i)

See also positional systems of numeral system for bases which might not be listed here.

Notes

↑ Rowlett, Russ (2001-11-01). "Names for large numbers". University of North Carolina. http://www.unc.edu/~rowlett/units/large.html. Retrieved 2008-01-31.

External links

The Database of Number Correlations: 1 to 2000+
What's Special About This Number? A Zoology of Numbers: from 0 to 500
See how to write big numbers
The MegaPenny Project - Visualizing big numbers
About big numbers
Robert P. Munafo's Large Numbers page
Different notations for big numbers - by Susan Stepney
Names for Large Numbers, in How Many? A Dictionary of Units of Measurement by Russ Rowlett
What's Special About This Number? (from 0 to 9999)

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