639748708 has 6 divisors (see below), whose sum is σ = 1119560246. Its totient is φ = 319874352.

The previous prime is 639748699. The next prime is 639748771. The reversal of 639748708 is 807847936.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 496754944 + 142993764 = 22288^2 + 11958^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79968585 + ... + 79968592.

Almost surely, 2^639748708 is an apocalyptic number.

It is an amenable number.

639748708 is a deficient number, since it is larger than the sum of its proper divisors (479811538).

639748708 is a wasteful number, since it uses less digits than its factorization.

639748708 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159937181 (or 159937179 counting only the distinct ones).

The product of its (nonzero) digits is 2032128, while the sum is 52.

The square root of 639748708 is about 25293.2541994896. The cubic root of 639748708 is about 861.6610712053.

The spelling of 639748708 in words is "six hundred thirty-nine million, seven hundred forty-eight thousand, seven hundred eight".