639443876 has 24 divisors (see below), whose sum is σ = 1127206080. Its totient is φ = 317392992.

The previous prime is 639443837. The next prime is 639443891. The reversal of 639443876 is 678344936.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 695345 + ... + 696263.

It is an arithmetic number, because the mean of its divisors is an integer number (46966920).

Almost surely, 2^639443876 is an apocalyptic number.

It is an amenable number.

639443876 is a deficient number, since it is larger than the sum of its proper divisors (487762204).

639443876 is a wasteful number, since it uses less digits than its factorization.

639443876 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2003 (or 2001 counting only the distinct ones).

The product of its digits is 2612736, while the sum is 50.

The square root of 639443876 is about 25287.2275269552. The cubic root of 639443876 is about 861.5241926707.

The spelling of 639443876 in words is "six hundred thirty-nine million, four hundred forty-three thousand, eight hundred seventy-six".