26 (number)

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26 20 6

26 (twenty-six) is the natural number following 25 and preceding 27.

Cardinal 26
twenty-six
Ordinal 26th
twenty-sixth
Factorization 2 \cdot 13
Divisors 1, 2, 13, 26
Roman numeral XXVI
Binary 11010
Ternary 222
Octal 32
Duodecimal 22
Hexadecimal 1A

Contents

[edit] In mathematics

[edit] Inherent mathematical properties

Twenty-six is a composite number, its proper divisors being 1, 2, and 13. 26 is the only number between a square number and a cube number, the numbers being 25 (5 squared) and 27 (3 cubed). This was first proved by Pierre de Fermat.

It is the 7th distinct biprime (2.13) and the 5th with 2 as its lowest non-unitary prime factor. The aliquot sum of 26 is 16 with an aliquot sequence of 8 members ; (26,16,15,9,4,3,1,0), leading to 0 through the prime 3 the 6th composite number so to do and so the sixth member of the 3-aliquot tree.

There is no solution to the equation φ(x) = 26, making 26 a nontotient. Nor is there a solution to x - φ(x) = 26, making 26 a noncototient.

In the classification of finite simple groups there are 26 sporadic groups.

[edit] Properties of its positional representation in certain radixes

Twenty six is a repdigit in base three (222) and in base twelve (22).

In base ten, 26 is the smallest number that is not a palindrome to have a square which is (26^2=676).

Twenty-six is the number of five-digit prime quadruplets, the first of which is {13001, 13003, 13007, 13009}[1].

[edit] In science

[edit] Astronomy

  • The Saros number of the lunar eclipse series which began on -1937 August 28 and ended on -386 March 17. The duration of Saros series 26 was 1550.5 years, and it contained 87 lunar eclipses.

[edit] In religion

[edit] In other fields

Twenty-six is:

[edit] Calendar years

In the Julian and Gregorian calendars:

[edit] References

  1. ^ Number of n-digit prime quadruplets
  2. ^ D. Kunkle and G. Cooperman, "Twenty-Six Moves Suffice for Rubik's Cube", Proc. of International Symposium on Symbolic and Algebraic Computation (ISSAC '07), ACM Press, 2007, 235--242.
  3. ^ "Twenty-six." Encyclopædia Britannica. Encyclopædia Britannica 2007 Ultimate Reference Suite. Chicago: Encyclopædia Britannica, 2007.