639912740 has 24 divisors (see below), whose sum is σ = 1346896320. Its totient is φ = 255378528.

The previous prime is 639912733. The next prime is 639912769. The reversal of 639912740 is 47219936.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27662 + ... + 45221.

It is an arithmetic number, because the mean of its divisors is an integer number (56120680).

Almost surely, 2^639912740 is an apocalyptic number.

It is an amenable number.

639912740 is an abundant number, since it is smaller than the sum of its proper divisors (706983580).

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

639912740 is a wasteful number, since it uses less digits than its factorization.

639912740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73331 (or 73329 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 41.

The square root of 639912740 is about 25296.4965953786. The cubic root of 639912740 is about 861.7347084053.

The spelling of 639912740 in words is "six hundred thirty-nine million, nine hundred twelve thousand, seven hundred forty".