639372870 has 24 divisors (see below), whose sum is σ = 1662369696. Its totient is φ = 170499408.

The previous prime is 639372869. The next prime is 639372887. The reversal of 639372870 is 78273936.

It is a happy number.

639372870 is a `hidden beast` number, since 639 + 3 + 7 + 2 + 8 + 7 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3551982 + ... + 3552161.

It is an arithmetic number, because the mean of its divisors is an integer number (69265404).

Almost surely, 2^639372870 is an apocalyptic number.

639372870 is an abundant number, since it is smaller than the sum of its proper divisors (1022996826).

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

639372870 is a wasteful number, since it uses less digits than its factorization.

639372870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7104156 (or 7104153 counting only the distinct ones).

The product of its (nonzero) digits is 381024, while the sum is 45.

The square root of 639372870 is about 25285.8234985535. The cubic root of 639372870 is about 861.4923026417.

The spelling of 639372870 in words is "six hundred thirty-nine million, three hundred seventy-two thousand, eight hundred seventy".