638879625 has 48 divisors (see below), whose sum is σ = 1201809024. Its totient is φ = 325908000.

The previous prime is 638879611. The next prime is 638879663. The reversal of 638879625 is 526978836.

It is a happy number.

638879625 is a `hidden beast` number, since 6 + 3 + 8 + 8 + 7 + 9 + 625 = 666.

It is not a de Polignac number, because 638879625 - 2⁴ = 638879609 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 13530 + ... + 38220.

It is an arithmetic number, because the mean of its divisors is an integer number (25037688).

Almost surely, 2^638879625 is an apocalyptic number.

It is an amenable number.

638879625 is a deficient number, since it is larger than the sum of its proper divisors (562929399).

638879625 is a wasteful number, since it uses less digits than its factorization.

638879625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24735 (or 24722 counting only the distinct ones).

The product of its digits is 4354560, while the sum is 54.

The square root of 638879625 is about 25276.0682266843. The cubic root of 638879625 is about 861.2707125453.

The spelling of 638879625 in words is "six hundred thirty-eight million, eight hundred seventy-nine thousand, six hundred twenty-five".