638975331 has 16 divisors (see below), whose sum is σ = 955319200. Its totient is φ = 422073504.

The previous prime is 638975321. The next prime is 638975333. The reversal of 638975331 is 133579836.

638975331 is a `hidden beast` number, since 638 + 9 + 7 + 5 + 3 + 3 + 1 = 666.

It is not a de Polignac number, because 638975331 - 2¹⁷ = 638844259 is a prime.

It is a super-2 number, since 2×638975331² = 816578947253119122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638975333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 105616 + ... + 111501.

It is an arithmetic number, because the mean of its divisors is an integer number (59707450).

Almost surely, 2^638975331 is an apocalyptic number.

638975331 is a deficient number, since it is larger than the sum of its proper divisors (316343869).

638975331 is a wasteful number, since it uses less digits than its factorization.

638975331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217235 (or 217229 counting only the distinct ones).

The product of its digits is 408240, while the sum is 45.

The square root of 638975331 is about 25277.9613695409. The cubic root of 638975331 is about 861.3137173388.

The spelling of 638975331 in words is "six hundred thirty-eight million, nine hundred seventy-five thousand, three hundred thirty-one".