639745948 has 12 divisors (see below), whose sum is σ = 1125742072. Its totient is φ = 318105360.

The previous prime is 639745937. The next prime is 639745969. The reversal of 639745948 is 849547936.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 441090 + ... + 442537.

Almost surely, 2^639745948 is an apocalyptic number.

It is an amenable number.

639745948 is a deficient number, since it is larger than the sum of its proper divisors (485996124).

639745948 is a wasteful number, since it uses less digits than its factorization.

639745948 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 883812 (or 883810 counting only the distinct ones).

The product of its digits is 6531840, while the sum is 55.

The square root of 639745948 is about 25293.1996394288. The cubic root of 639745948 is about 861.6598320792.

The spelling of 639745948 in words is "six hundred thirty-nine million, seven hundred forty-five thousand, nine hundred forty-eight".