639831632 has 20 divisors (see below), whose sum is σ = 1352371776. Its totient is φ = 290832480.

The previous prime is 639831613. The next prime is 639831637. The reversal of 639831632 is 236138936.

It is a self number, because there is not a number n which added to its sum of digits gives 639831632.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639831637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1817528 + ... + 1817879.

Almost surely, 2^639831632 is an apocalyptic number.

It is an amenable number.

639831632 is an abundant number, since it is smaller than the sum of its proper divisors (712540144).

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

639831632 is a wasteful number, since it uses less digits than its factorization.

639831632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3635426 (or 3635420 counting only the distinct ones).

The product of its digits is 139968, while the sum is 41.

The square root of 639831632 is about 25294.8933976801. The cubic root of 639831632 is about 861.6982989974.

The spelling of 639831632 in words is "six hundred thirty-nine million, eight hundred thirty-one thousand, six hundred thirty-two".