639372874 has 12 divisors (see below), whose sum is σ = 1115640594. Its totient is φ = 274016904.

The previous prime is 639372869. The next prime is 639372887. The reversal of 639372874 is 478273936.

It can be written as a sum of positive squares in only one way, i.e., 635392849 + 3980025 = 25207^2 + 1995^2 .

It is a Harshad number since it is a multiple of its sum of digits (49).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3262009 + ... + 3262204.

Almost surely, 2^639372874 is an apocalyptic number.

639372874 is a deficient number, since it is larger than the sum of its proper divisors (476267720).

639372874 is a wasteful number, since it uses less digits than its factorization.

639372874 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6524229 (or 6524222 counting only the distinct ones).

The product of its digits is 1524096, while the sum is 49.

The square root of 639372874 is about 25285.8235776492. The cubic root of 639372874 is about 861.4923044382.

The spelling of 639372874 in words is "six hundred thirty-nine million, three hundred seventy-two thousand, eight hundred seventy-four".