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
Curiosity: What's Inside the Cube? messages. Players tapped the cubelets to dig through the surface of each layer and reveal the next layer below. The goal was to reach the center and to discover what was inside the cube. Each layer, which had a distinct look or design, contained a clue as to what was in the centre of the cube. Each cubelet destroyed by a player awarded them coins. Coins could be spent on tools that temporarily enhanced the player's abilities, such as picks ranging from iron to steel to diamond that increased the number of cubelets destroyed with each tap, or firecrackers that