638985584 has 10 divisors (see below), whose sum is σ = 1238034600. Its totient is φ = 319492784.

The previous prime is 638985583. The next prime is 638985601. The reversal of 638985584 is 485589836.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638985583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19968284 + ... + 19968315.

It is an arithmetic number, because the mean of its divisors is an integer number (123803460).

Almost surely, 2^638985584 is an apocalyptic number.

It is an amenable number.

638985584 is a deficient number, since it is larger than the sum of its proper divisors (599049016).

638985584 is a wasteful number, since it uses less digits than its factorization.

638985584 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39936607 (or 39936601 counting only the distinct ones).

The product of its digits is 8294400, while the sum is 56.

The square root of 638985584 is about 25278.1641738478. The cubic root of 638985584 is about 861.3183241950.

The spelling of 638985584 in words is "six hundred thirty-eight million, nine hundred eighty-five thousand, five hundred eighty-four".