639025832 has 8 divisors (see below), whose sum is σ = 1198173450. Its totient is φ = 319512912.

The previous prime is 639025811. The next prime is 639025837. The reversal of 639025832 is 238520936.

It can be written as a sum of positive squares in only one way, i.e., 462508036 + 176517796 = 21506^2 + 13286^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (639025837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39939107 + ... + 39939122.

Almost surely, 2^639025832 is an apocalyptic number.

It is an amenable number.

639025832 is a deficient number, since it is larger than the sum of its proper divisors (559147618).

639025832 is a wasteful number, since it uses less digits than its factorization.

639025832 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79878235 (or 79878231 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 38.

The square root of 639025832 is about 25278.9602634286. The cubic root of 639025832 is about 861.3364078643.

The spelling of 639025832 in words is "six hundred thirty-nine million, twenty-five thousand, eight hundred thirty-two".