639156996 has 18 divisors (see below), whose sum is σ = 1615646942. Its totient is φ = 213052320.

The previous prime is 639156967. The next prime is 639157033. The reversal of 639156996 is 699651936.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 629006400 + 10150596 = 25080^2 + 3186^2 .

It is a tau number, because it is divible by the number of its divisors (18).

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, 8877145 + ... + 8877216.

Almost surely, 2^639156996 is an apocalyptic number.

It is an amenable number.

639156996 is an abundant number, since it is smaller than the sum of its proper divisors (976489946).

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

639156996 is a wasteful number, since it uses less digits than its factorization.

639156996 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17754371 (or 17754366 counting only the distinct ones).

The product of its digits is 2361960, while the sum is 54.

The square root of 639156996 is about 25281.5544617019. The cubic root of 639156996 is about 861.3953353725.

The spelling of 639156996 in words is "six hundred thirty-nine million, one hundred fifty-six thousand, nine hundred ninety-six".