639308680 has 32 divisors (see below), whose sum is σ = 1441252440. Its totient is φ = 255224320.

The previous prime is 639308671. The next prime is 639308701. The reversal of 639308680 is 86803936.

It can be written as a sum of positive squares in 4 ways, for example, as 519931204 + 119377476 = 22802^2 + 10926^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5502 + ... + 36178.

Almost surely, 2^639308680 is an apocalyptic number.

It is an amenable number.

639308680 is an abundant number, since it is smaller than the sum of its proper divisors (801943760).

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

639308680 is a wasteful number, since it uses less digits than its factorization.

639308680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31209 (or 31205 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 43.

The square root of 639308680 is about 25284.5541783912. The cubic root of 639308680 is about 861.4634717647.

The spelling of 639308680 in words is "six hundred thirty-nine million, three hundred eight thousand, six hundred eighty".