639425648 has 30 divisors (see below), whose sum is σ = 1251364104. Its totient is φ = 316524768.

The previous prime is 639425629. The next prime is 639425671. The reversal of 639425648 is 846524936.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 167861 + ... + 171627.

Almost surely, 2^639425648 is an apocalyptic number.

It is an amenable number.

639425648 is a deficient number, since it is larger than the sum of its proper divisors (611938456).

639425648 is a wasteful number, since it uses less digits than its factorization.

639425648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3981 (or 3872 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 47.

The square root of 639425648 is about 25286.8671052782. The cubic root of 639425648 is about 861.5160063843.

The spelling of 639425648 in words is "six hundred thirty-nine million, four hundred twenty-five thousand, six hundred forty-eight".