639797944 has 32 divisors (see below), whose sum is σ = 1264032000. Its totient is φ = 302756832.

The previous prime is 639797909. The next prime is 639798013. The reversal of 639797944 is 449797936.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 239287 + ... + 241945.

It is an arithmetic number, because the mean of its divisors is an integer number (39501000).

Almost surely, 2^639797944 is an apocalyptic number.

It is an amenable number.

639797944 is a deficient number, since it is larger than the sum of its proper divisors (624234056).

639797944 is a wasteful number, since it uses less digits than its factorization.

639797944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4267 (or 4263 counting only the distinct ones).

The product of its digits is 10287648, while the sum is 58.

The square root of 639797944 is about 25294.2274837561. The cubic root of 639797944 is about 861.6831755387.

The spelling of 639797944 in words is "six hundred thirty-nine million, seven hundred ninety-seven thousand, nine hundred forty-four".