26

26 = 2 x 13.

26 is the only integer sandwiched between a square (25) and a cube (27).

26 is the smallest non-palindromic number whose square is palindromic: 26² = 676.

26 is equal to the sum of the digits of its cube: 26³ = 17,576 and 1 + 7 + 5 + 7 + 6 = 26.

26 (together with 11) cannot be represented as the sum of less than six hexagonal numbers from the sequence 1 6 15 28 45 . . . .

26 has a representation as a sum of two squares: 26 = 5² + 1².

26 is the smallest number with three representations as a sum of three distinct primes: 26 = 2 + 5 + 19 = 2 + 7 + 17 = 2 + 11 + 13.


26 is the atomic number of iron and the number of letters in the English alphabet.

Source: Number Gossip