64 (number) it is possible to find sequences of 64 consecutive integers such that each inner member shares a factor with either the first or the last member, 64 is an Erdős–Woods number. In base 10, no integer added up to its own digits yields 64, hence it is a self number. 64 is a superperfect number—a number such that σ(σ("n")) = 2"n". 64 is the index of Graham's number in the rapidly growing sequence 3↑↑↑↑3, 3 ↑ 3,… Sixty-four is: 64 (number) 64 (sixty-four) is the natural number following 63 and preceding 65. Sixty-four is the square of 8, the cube
Powerful number Powerful number A powerful number is a positive integer "m" such that for every prime number "p" dividing "m", "p" also divides "m". Equivalently, a powerful number is the product of a square and a cube, that is, a number "m" of the form "m" = "a""b", where "a" and "b" are positive integers. Powerful numbers are also known as squareful, square-full, or 2-full. Paul Erdős and George Szekeres studied such numbers and Solomon W. Golomb named such numbers "powerful". The following is a list of all powerful numbers between 1 and 1000: If "m" = "a""b", then every prime