64

64 is a positive integer between 63 and 65.

Properties
64 is the square of 8, the cube of 4, and the sixth power of two.

It is the smallest power of two that is adjacent to neither a mersenne prime or a fermat prime, and the third integer to be both a square and a cube (after 0 and 1)

It is a deficient number, but only by a bit - like other powers of two, the sum of its factors is one less than it.