400 (number)

400
Cardinal four hundred
Ordinal 400th
(four hundredth)
Factorization 2^4 \cdot 5^2
Divisors 1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 200, 400
Roman numeral CD
Binary 1100100002
Octal 6208
Duodecimal 29412
Hexadecimal 19016
Hebrew ת (Tav)

400 (four hundred) is the natural number following 399 and preceding 401. (For the year 400 AD, see 400)

Contents

Mathematical properties

400 is the square of 20.

A circle is divided into 400 grads, which is equal to 360 degrees and 2π radians. (Degrees and radians are the SI accepted units).

400 is a self number in base 10, since there is no integer that added to the sum of its own digits results in 400. On the other hand, 400 is divisible by the sum of its own base 10 digits, making it a Harshad number.

Other fields

Four hundred is also

Integers from 401 to 499

401 prime number, tetranacci number, sum of seven consecutive primes (43 + 47 + 53 + 59 + 61 + 67 + 71), sum of nine consecutive primes (29 + 31 + 37 + 41 + 43 + 47 + 53 + 59 + 61), Chen prime, Eisenstein prime with no imaginary part, Mertens function returns 0, member of the Mian–Chowla sequence. Also HTTP status code for an unauthorized request, area code for Rhode Island, also in the name of a retirement plan, 401(k). Stephen Colbert's Formula 401, a "man seed" based product brand his persona on The Colbert Report promotes for sale to the public [1].


402 = 2 × 3 × 67, sphenic number, nontotient, Harshad number, also HTTP status code for payment required, area code for Nebraska


403 = 13 × 31, Mertens function returns 0. Also, HTTP status code for forbidden; also in the name of a retirement plan in the United States, 403(b). The area code for southern Alberta.


404 = 22 × 101, Mertens function returns 0, nontotient, noncototient. Also, HTTP status code for "Not found", perhaps the most famous HTTP status code. Section 404 of the Sarbanes–Oxley Act. One of the three area codes of the Atlanta calling area.


405 = 34 × 5, Mertens function returns 0, Harshad number; HTTP error code for "Method not allowed". Area code for central Oklahoma, including Oklahoma City and surrounding suburbs.


406 = 2 × 7 × 29, sphenic number, triangular number, centered nonagonal number, nontotient, and HTTP error code for "Not acceptable".

406 is a poem by John Boyle O'Reilly. It was believed to have been the number of one of O'Reilly's prison cells, and was the number of his first hotel room after he arrived in the United States. Hence the number had a mystical significance to him, as intimated in the poem.

See also the Peugeot 406 car.


407 = 11 × 37,


408 = 23 × 3 × 17


409 is a prime number, Chen prime, centered triangular number.

410s

410 = 2 × 5 × 41, sphenic number, sum of six consecutive primes (59 + 61 + 67 + 71 + 73 + 79), nontotient, Harshad number, HTTP error code for "gone".


411 = 3 × 137, self number, HTTP error code for "Length required", slang for information (see 4-1-1)


412 = 22 × 103, nontotient, noncototient, sum of twelve consecutive primes (13 + 17 + 19 + 23 + 29 + 31 + 37 + 41 + 43 + 47 + 53 + 59), HTTP error code for "Precondition failed", Area code for Pittsburgh, Pennsylvania.


413 = 7 × 59, Mertens function returns 0, self number, HTTP error code for "Request entity too large", area code for Western Massachusetts.


414 = 2 × 32 × 23, Mertens function returns 0, nontotient, Harshad number, HTTP error code for "Request URI too long", Area code for Milwaukee, Wisconsin.


415 = 5 × 83, HTTP error code for "unsupported media type"


416 = 25 × 13, HTTP error code for "Requested Range not satisfiable"


417 = 3 × 139, HTTP error code for "Expectation failed". Also the area code for southwestern Missouri, including Springfield, and Joplin.


418 = 2 × 11 × 19, sphenic number the number of Abrahadabra, Hyper Text Coffee Pot Control Protocol error code for a teapot.


419 prime number, Sophie Germain prime, Chen prime, Eisenstein prime with no imaginary part, highly cototient number, Mertens function returns 0, also refers to the Nigerian advance fee fraud scheme (after the section of the Nigerian Criminal Code it violates)

420s

420 has its own article.


421 prime number, sum of five consecutive primes (73 + 79 + 83 + 89 + 97), centered square number, also SMTP code meaning the transmission channel will be closing


422 = 2 × 211, Mertens function returns 0, nontotient


423 = 32 × 47, Mertens function returns 0, Harshad number


424 = 23 × 53, sum of ten consecutive primes (23 + 29 + 31 + 37 + 41 + 43 + 47 + 53 + 59 + 61), Mertens function returns 0, refactorable number, self number


425 = 52 × 17, sum of three consecutive primes (137 + 139 + 149), Mertens function returns 0


426 = 2 × 3 × 71, sphenic number, nontotient, untouchable number


427 = 7 × 61, Mertens function returns 0


428 = 22 × 107, Mertens function returns 0, nontotient


429 = 3 × 11 × 13, sphenic number, Catalan number

430s

430 = 2 × 5 × 43, sphenic number, untouchable number


431 prime number, Sophie Germain prime, sum of seven consecutive primes (47 + 53 + 59 + 61 + 67 + 71 + 73), Chen prime, Eisenstein prime with no imaginary part


432 sum of four consecutive primes (103 + 107 + 109 + 113), a highly totient number, sum of totient function for first 37 integers and a Harshad number. 42 x 33= 33 x 24 =432. 432 is also three-dozen sets of a dozen, making it three gross.


433 prime number, Markov number, star number. The perfect score in the game show Fifteen To One, only ever achieved once in over 2000 shows.


434 = 2 × 7 × 31, sphenic number, sum of six consecutive primes (61 + 67 + 71 + 73 + 79 + 83)nontotient


435 = 3 × 5 × 29, sphenic number, triangular number, hexagonal number, self number


436 = 22 × 109, nontotient, noncototient


437 = 19 × 23


438 = 2 × 3 × 73, sphenic number, Smith number. The "438 match" or "438 game" has been used by cricket media to describe the famous 2006 One Day International in which Australia scored a world record 434 in their innings, only to see South Africa respond in their innings with 438.


439 prime number, sum of three consecutive primes (139 + 149 + 151), sum of nine consecutive primes (31 + 37 + 41 + 43 + 47 + 53 + 59 + 61 + 67), strictly non-palindromic number

440s

440 = 23 × 5 × 11, the sum of the first seventeen prime numbers, Harshad number, also, in hertz, the standard frequency to which most orchestras tune the pitch A above middle C. A few orchestras tune slightly flatter or sharper than this.


441 = 32 × 72 = 212


442 = 2 × 13 × 17, sphenic number, sum of eight consecutive primes (41 + 43 + 47 + 53 + 59 + 61 + 67 + 71)


443 prime number, Sophie Germain prime, Chen prime,+ Eisenstein prime with no imaginary part, Mertens function sets new low of -9, which stands until 659


444 = 22 × 3 × 37, refactorable number, Harshad number


445 = 5 × 89


446 = 2 × 223, nontotient, self number


447 = 3 × 149


448 = 26 × 7, untouchable number, refactorable number, Harshad number


449 prime number, sum of five consecutive primes (79 + 83 + 89 + 97 + 101), Chen prime, Eisenstein prime with no imaginary part, Proth prime. Also the largest number whose factorial is less than 101000

450s

450 = 2 × 32 × 52, nontotient, sum of totient function for first 38 integers, refactorable number, Harshad number, also SMTP code meaning the requested mail action was not carried out, a perfect score in Canadian five-pin bowling and an area code in Southern Quebec.


451 is a Wedderburn–Etherington number and a centered decagonal number; its reciprocal has period 10; 451 is the smallest number with this period reciprocal length.

The number also has significance in Ray Bradbury's novel Fahrenheit 451, as it is the temperature at which the paper in books ignites.


452 = 22 × 113, also SMTP code meaning that the requested mail action was not carried out because of insufficient system storage


453 = 3 × 151


454 = 2 × 227, nontotient, a Smith number


455 = 5 × 7 × 13, sphenic number, tetrahedral number


456 = 23 × 3 × 19, sum of a twin prime (227 + 229), sum of four consecutive primes (107 + 109 + 113 + 127), centered pentagonal number


457 prime number, sum of three consecutive primes (149 + 151 + 157), self number


458 = 2 × 229, nontotient


459 = 33 × 17

460s

460 = 22 × 5 × 23, centered triangular number, Harshad number, sum of twelve consecutive primes (17 + 19 + 23 + 29 + 31 + 37 + 41 + 43 + 47 + 53 + 59 + 61)


461 prime number, Chen prime, Eisenstein prime with no imaginary part


462 = 2 × 3 × 7 × 11, sum of six consecutive primes (67 + 71 + 73 + 79 + 83 + 89), pronic number, sparsely totient number


463 prime number, sum of seven consecutive primes (53 + 59 + 61 + 67 + 71 + 73 + 79), centered heptagonal number, number of days in the synodic period of Ceres


464 = 24 × 29


465 = 3 × 5 × 31, sphenic number, triangular number, member of the Padovan sequence, Harshad number


466 = 2 × 233, noncototient


467 prime number, safe prime, Chen prime, Eisenstein prime with no imaginary part


468 = 22 × 32 × 13, sum of ten consecutive primes (29 + 31 + 37 + 41 + 43 + 47 + 53 + 59 + 61 + 67), refactorable number, self number, Harshad number


469 = 7 × 67, centered hexagonal number

470s

470 = 2 × 5 × 47, sphenic number, nontotient, noncototient


471 = 3 × 157, sum of three consecutive primes (151 + 157 + 163), perfect totient number


472 = 23 × 59, nontotient, untouchable number, refactorable number


473 = 11 × 43, sum of five consecutive primes (83 + 89 + 97 + 101 + 103)


474 = 2 × 3 × 79, sphenic number, sum of eight consecutive primes (43 + 47 + 53 + 59 + 61 + 67 + 71 + 73), nontotient, noncototient, sum of totient function for first 39 integers, untouchable number, nonagonal number


475 is a 49-gonal number, member of the Mian–Chowla sequence.


476 = 22 × 7 × 17, Harshad number


477 = 32 × 53


478 = 2 × 239


479 prime number, safe prime, sum of nine consecutive primes (37 + 41 + 43 + 47 + 53 + 59 + 61 + 67 + 71), Chen prime, Eisenstein prime with no imaginary part, self number

480s

480 = 25 × 3 × 5, sum of a twin prime (239 + 241), sum of four consecutive primes (109 + 113 + 127 + 131), highly totient number, refactorable number, Harshad number


481 = 13 × 37, octagonal number, centered square number, Harshad number


482 = 2 × 241, nontotient, noncototient


483 = 3 × 7 × 23, sphenic number, Smith number


484 = 22 × 112 = 222, nontotient


485 = 5 × 97


486 = 2 × 35, Harshad number, also shorthand for the Intel 80486 microprocessor chip


487 prime number, sum of three consecutive primes (157 + 163 + 167), Chen prime, shorthand for the Intel 80487 floating point processor chip.


488 = 23 × 61, nontotient, refactorable number


489 = 3 × 163, octahedral number

490s

490 = 2 × 5 × 72, noncototient, sum of totient function for first 40 integers, self number.


491 prime number, Sophie Germain prime, Chen prime, Eisenstein prime with no imaginary part, strictly non-palindromic number


492 = 22 × 3 × 41, sum of six consecutive primes (71 + 73 + 79 + 83 + 89 + 97), refactorable number, member of a Ruth–Aaron pair with 493 under first definition


493 = 17 × 29, sum of seven consecutive primes (59 + 61 + 67 + 71 + 73 + 79 + 83), member of a Ruth–Aaron pair with 493 under first definition


494 = 2 × 13 × 19, sphenic number, nontotient


495 has its own article.


496 has its own article.


497 = 7 × 71, sum of five consecutive primes (89 + 97 + 101 + 103 + 107)


498 = 2 × 3 × 83, sphenic number, untouchable number


499 prime number, Chen prime

References