638438025 has 48 divisors (see below), whose sum is σ = 1137070080. Its totient is φ = 315163200.

The previous prime is 638438011. The next prime is 638438033. The reversal of 638438025 is 520834836.

It is not a de Polignac number, because 638438025 - 2⁵ = 638437993 is a prime.

It is a super-2 number, since 2×638438025² = 815206223531801250, which contains 22 as substring.

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, 47506 + ... + 59444.

It is an arithmetic number, because the mean of its divisors is an integer number (23688960).

Almost surely, 2^638438025 is an apocalyptic number.

It is an amenable number.

638438025 is a deficient number, since it is larger than the sum of its proper divisors (498632055).

638438025 is a wasteful number, since it uses less digits than its factorization.

638438025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12006 (or 12001 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 39.

The square root of 638438025 is about 25267.3311807955. The cubic root of 638438025 is about 861.0722271570.

The spelling of 638438025 in words is "six hundred thirty-eight million, four hundred thirty-eight thousand, twenty-five".