639633430902 has 64 divisors (see below), whose sum is σ = 1306402366464. Its totient is φ = 208732567680.

The previous prime is 639633430879. The next prime is 639633430907. The reversal of 639633430902 is 209034336936.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639633430907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 177034848 + ... + 177038460.

It is an arithmetic number, because the mean of its divisors is an integer number (20412536976).

Almost surely, 2^639633430902 is an apocalyptic number.

639633430902 is an abundant number, since it is smaller than the sum of its proper divisors (666768935562).

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

639633430902 is a wasteful number, since it uses less digits than its factorization.

639633430902 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6493.

The product of its (nonzero) digits is 1889568, while the sum is 48.

The spelling of 639633430902 in words is "six hundred thirty-nine billion, six hundred thirty-three million, four hundred thirty thousand, nine hundred two".