64 (number) 64 (number) 64 (sixty-four) is the natural number following 63 and preceding 65. Sixty-four is the square of 8, the cube of 4, and the sixth power of 2. It is the smallest number with exactly seven divisors. It is the lowest positive power of two that is adjacent to neither a Mersenne prime nor a Fermat prime. 64 is the sum of Euler's totient function for the first fourteen integers. It is also a dodecagonal number and a centered triangular number. 64 is also the first whole number that is both a perfect square and a perfect cube. Since
Cube Zero forest with her daughter. Rains wakes up in the Cube and meets the other occupants: one of them, Robert Haskell, has the same tattoo on his forehead as the soldier who captured her. However, Haskell, like everyone else, only knows his own name and has no recollection of his former life or how he got there. According to what Wynn and Dodd know, everyone in the Cube faced a death sentence and volunteered to partake in psychological experiments instead. Rains' consent form, however, is not found in her file. The captives venture through the Cube, testing each room for traps