639686088 has 48 divisors (see below), whose sum is σ = 1734068700. Its totient is φ = 213033600.

The previous prime is 639686087. The next prime is 639686111. The reversal of 639686088 is 880686936.

It can be written as a sum of positive squares in 2 ways, for example, as 563682564 + 76003524 = 23742^2 + 8718^2 .

It is a super-5 number, since 5×639686088⁵ (a number of 45 digits) contains 55555 as substring.

It is not an unprimeable number, because it can be changed into a prime (639686087) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 90258 + ... + 97086.

Almost surely, 2^639686088 is an apocalyptic number.

It is an amenable number.

639686088 is an abundant number, since it is smaller than the sum of its proper divisors (1094382612).

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

639686088 is a wasteful number, since it uses less digits than its factorization.

639686088 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8142 (or 8135 counting only the distinct ones).

The product of its (nonzero) digits is 2985984, while the sum is 54.

The square root of 639686088 is about 25292.0162897306. The cubic root of 639686088 is about 861.6329565325.

The spelling of 639686088 in words is "six hundred thirty-nine million, six hundred eighty-six thousand, eighty-eight".