639165990 has 16 divisors (see below), whose sum is σ = 1533998448. Its totient is φ = 170444256.

The previous prime is 639165959. The next prime is 639166039. The reversal of 639165990 is 99561936.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10652737 + ... + 10652796.

It is an arithmetic number, because the mean of its divisors is an integer number (95874903).

Almost surely, 2^639165990 is an apocalyptic number.

639165990 is an abundant number, since it is smaller than the sum of its proper divisors (894832458).

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

639165990 is a wasteful number, since it uses less digits than its factorization.

639165990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21305543.

The product of its (nonzero) digits is 393660, while the sum is 48.

The square root of 639165990 is about 25281.7323377968. The cubic root of 639165990 is about 861.3993757743.

The spelling of 639165990 in words is "six hundred thirty-nine million, one hundred sixty-five thousand, nine hundred ninety".