639388400 has 60 divisors (see below), whose sum is σ = 1755585552. Its totient is φ = 219217920.

The previous prime is 639388367. The next prime is 639388427. The reversal of 639388400 is 4883936.

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 11 ways as a sum of consecutive naturals, for example, 111377 + ... + 116976.

Almost surely, 2^639388400 is an apocalyptic number.

It is an amenable number.

639388400 is an abundant number, since it is smaller than the sum of its proper divisors (1116197152).

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

639388400 is a wasteful number, since it uses less digits than its factorization.

639388400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228378 (or 228367 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 41.

The square root of 639388400 is about 25286.1305857579. The cubic root of 639388400 is about 861.4992776364.

The spelling of 639388400 in words is "six hundred thirty-nine million, three hundred eighty-eight thousand, four hundred".