638474913 has 8 divisors (see below), whose sum is σ = 945888800. Its totient is φ = 425649924.

The previous prime is 638474891. The next prime is 638474939. The reversal of 638474913 is 319474836.

638474913 is a `hidden beast` number, since 638 + 4 + 7 + 4 + 9 + 1 + 3 = 666.

It is not a de Polignac number, because 638474913 - 2⁸ = 638474657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638474113) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 11823583 + ... + 11823636.

It is an arithmetic number, because the mean of its divisors is an integer number (118236100).

Almost surely, 2^638474913 is an apocalyptic number.

It is an amenable number.

638474913 is a deficient number, since it is larger than the sum of its proper divisors (307413887).

638474913 is a wasteful number, since it uses less digits than its factorization.

638474913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23647228 (or 23647222 counting only the distinct ones).

The product of its digits is 435456, while the sum is 45.

The square root of 638474913 is about 25268.0611246688. The cubic root of 638474913 is about 861.0888106620.

The spelling of 638474913 in words is "six hundred thirty-eight million, four hundred seventy-four thousand, nine hundred thirteen".