643538859264 has 108 divisors (see below), whose sum is σ = 2120549974816. Its totient is φ = 183868240896.

The previous prime is 643538859259. The next prime is 643538859281. The reversal of 643538859264 is 462958835346.

643538859264 is a `hidden beast` number, since 6 + 4 + 3 + 5 + 38 + 8 + 592 + 6 + 4 = 666.

643538859264 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19934854 + ... + 19967109.

Almost surely, 2^643538859264 is an apocalyptic number.

643538859264 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

643538859264 is an abundant number, since it is smaller than the sum of its proper divisors (1477011115552).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643538859264 is a wasteful number, since it uses less digits than its factorization.

643538859264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39901992 (or 39901975 counting only the distinct ones).

The product of its digits is 149299200, while the sum is 63.

The spelling of 643538859264 in words is "six hundred forty-three billion, five hundred thirty-eight million, eight hundred fifty-nine thousand, two hundred sixty-four".