639715172 has 12 divisors (see below), whose sum is σ = 1119846000. Its totient is φ = 319759176.

The previous prime is 639715159. The next prime is 639715187. The reversal of 639715172 is 271517936.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8858 + ... + 36849.

It is an arithmetic number, because the mean of its divisors is an integer number (93320500).

Almost surely, 2^639715172 is an apocalyptic number.

It is an amenable number.

639715172 is a deficient number, since it is larger than the sum of its proper divisors (480130828).

639715172 is a wasteful number, since it uses less digits than its factorization.

639715172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49210 (or 49208 counting only the distinct ones).

The product of its digits is 79380, while the sum is 41.

The square root of 639715172 is about 25292.5912472408. The cubic root of 639715172 is about 861.6460146838.

The spelling of 639715172 in words is "six hundred thirty-nine million, seven hundred fifteen thousand, one hundred seventy-two".