638566725 has 48 divisors (see below), whose sum is σ = 1124928000. Its totient is φ = 318697920.

The previous prime is 638566703. The next prime is 638566739. The reversal of 638566725 is 527665836.

It is not a de Polignac number, because 638566725 - 2⁵ = 638566693 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 115576 + ... + 120974.

It is an arithmetic number, because the mean of its divisors is an integer number (23436000).

Almost surely, 2^638566725 is an apocalyptic number.

It is an amenable number.

638566725 is a deficient number, since it is larger than the sum of its proper divisors (486361275).

638566725 is a wasteful number, since it uses less digits than its factorization.

638566725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5514 (or 5509 counting only the distinct ones).

The product of its digits is 1814400, while the sum is 48.

The square root of 638566725 is about 25269.8778192535. The cubic root of 638566725 is about 861.1300832294.

The spelling of 638566725 in words is "six hundred thirty-eight million, five hundred sixty-six thousand, seven hundred twenty-five".