639628888 has 16 divisors (see below), whose sum is σ = 1208060280. Its totient is φ = 317479488.

The previous prime is 639628883. The next prime is 639628897. The reversal of 639628888 is 888826936.

It is a super-2 number, since 2×639628888² = 818250228728233088, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639628883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 290706 + ... + 292897.

Almost surely, 2^639628888 is an apocalyptic number.

It is an amenable number.

639628888 is a deficient number, since it is larger than the sum of its proper divisors (568431392).

639628888 is a wasteful number, since it uses less digits than its factorization.

639628888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 583746 (or 583742 counting only the distinct ones).

The product of its digits is 7962624, while the sum is 58.

The square root of 639628888 is about 25290.8854728339. The cubic root of 639628888 is about 861.6072736884.

The spelling of 639628888 in words is "six hundred thirty-nine million, six hundred twenty-eight thousand, eight hundred eighty-eight".