240

240 = 2⁴ x 3 x 5.

240 is 11110000 in base 2 (binary).

240 is the number of equivalent hyperspheres in 8 dimensions that can touch an equivalent hypersphere without any intersections (kissing number).

240 is the smallest number with 20 divisors.

240 is a divisor of 31² - 1.

240 is a number that cannot be written as a sum of three squares.

240 is the number of distinct solutions of the Soma cube puzzle.

Source: Number Gossip