638861542564 has 24 divisors (see below), whose sum is σ = 1277778833408. Its totient is φ = 273785857920.

The previous prime is 638861542559. The next prime is 638861542589. The reversal of 638861542564 is 465245168836.

It is a junction number, because it is equal to n+sod(n) for n = 638861542499 and 638861542508.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 171229 + ... + 1143259.

Almost surely, 2^638861542564 is an apocalyptic number.

It is an amenable number.

638861542564 is an abundant number, since it is smaller than the sum of its proper divisors (638917290844).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

638861542564 is a wasteful number, since it uses less digits than its factorization.

638861542564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 995515 (or 995513 counting only the distinct ones).

The product of its digits is 33177600, while the sum is 58.

The spelling of 638861542564 in words is "six hundred thirty-eight billion, eight hundred sixty-one million, five hundred forty-two thousand, five hundred sixty-four".