638520324764 has 18 divisors (see below), whose sum is σ = 1299844947240. Its totient is φ = 273651567672.

The previous prime is 638520324733. The next prime is 638520324787. The reversal of 638520324764 is 467423025836.

638520324764 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1628878184 + ... + 1628878575.

It is an arithmetic number, because the mean of its divisors is an integer number (72213608180).

Almost surely, 2^638520324764 is an apocalyptic number.

It is an amenable number.

638520324764 is an abundant number, since it is smaller than the sum of its proper divisors (661324622476).

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

638520324764 is a wasteful number, since it uses less digits than its factorization.

638520324764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3257756777 (or 3257756768 counting only the distinct ones).

The product of its (nonzero) digits is 5806080, while the sum is 50.

The spelling of 638520324764 in words is "six hundred thirty-eight billion, five hundred twenty million, three hundred twenty-four thousand, seven hundred sixty-four".