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
Radical of an integer of the multiples of formula_10. Radical of an integer In number theory, the radical of a positive integer "n" is defined as the product of the distinct prime numbers dividing "n". Each prime factor of "n" occurs exactly once as a factor of this product: The radical plays a central role in the statement of the abc conjecture. Radical numbers for the first few positive integers are For example, and therefore The function formula_4 is multiplicative (but not completely multiplicative). The radical of any integer "n" is the largest square-free divisor of "n" and so also described as the square-free