639853924 has 12 divisors (see below), whose sum is σ = 1120143024. Its totient is φ = 319813064.

The previous prime is 639853897. The next prime is 639853927. The reversal of 639853924 is 429358936.

It is not an unprimeable number, because it can be changed into a prime (639853927) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 15142 + ... + 38845.

It is an arithmetic number, because the mean of its divisors is an integer number (93345252).

Almost surely, 2^639853924 is an apocalyptic number.

It is an amenable number.

639853924 is a deficient number, since it is larger than the sum of its proper divisors (480289100).

639853924 is a wasteful number, since it uses less digits than its factorization.

639853924 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56954 (or 56952 counting only the distinct ones).

The product of its digits is 1399680, while the sum is 49.

The square root of 639853924 is about 25295.3340361419. The cubic root of 639853924 is about 861.7083061902.

The spelling of 639853924 in words is "six hundred thirty-nine million, eight hundred fifty-three thousand, nine hundred twenty-four".