639907948 has 24 divisors (see below), whose sum is σ = 1202421024. Its totient is φ = 296889600.

The previous prime is 639907927. The next prime is 639907981. The reversal of 639907948 is 849709936.

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, 61443 + ... + 71098.

It is an arithmetic number, because the mean of its divisors is an integer number (50100876).

Almost surely, 2^639907948 is an apocalyptic number.

639907948 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

639907948 is a deficient number, since it is larger than the sum of its proper divisors (562513076).

639907948 is a wasteful number, since it uses less digits than its factorization.

639907948 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132633 (or 132631 counting only the distinct ones).

The product of its (nonzero) digits is 2939328, while the sum is 55.

The square root of 639907948 is about 25296.4018785281. The cubic root of 639907948 is about 861.7325573605.

The spelling of 639907948 in words is "six hundred thirty-nine million, nine hundred seven thousand, nine hundred forty-eight".