639823544 has 16 divisors (see below), whose sum is σ = 1200080400. Its totient is φ = 319802112.

The previous prime is 639823523. The next prime is 639823603. The reversal of 639823544 is 445328936.

639823544 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 639823495 and 639823504.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14504 + ... + 38600.

It is an arithmetic number, because the mean of its divisors is an integer number (75005025).

Almost surely, 2^639823544 is an apocalyptic number.

It is an amenable number.

639823544 is a deficient number, since it is larger than the sum of its proper divisors (560256856).

639823544 is a wasteful number, since it uses less digits than its factorization.

639823544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27422 (or 27418 counting only the distinct ones).

The product of its digits is 622080, while the sum is 44.

The square root of 639823544 is about 25294.7335230083. The cubic root of 639823544 is about 861.6946681228.

The spelling of 639823544 in words is "six hundred thirty-nine million, eight hundred twenty-three thousand, five hundred forty-four".