642513904 has 10 divisors (see below), whose sum is σ = 1244870720. Its totient is φ = 321256944.

The previous prime is 642513841. The next prime is 642513913. The reversal of 642513904 is 409315246.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 642513904.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20078544 + ... + 20078575.

It is an arithmetic number, because the mean of its divisors is an integer number (124487072).

Almost surely, 2^642513904 is an apocalyptic number.

It is an amenable number.

642513904 is a deficient number, since it is larger than the sum of its proper divisors (602356816).

642513904 is a wasteful number, since it uses less digits than its factorization.

642513904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40157127 (or 40157121 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 34.

The square root of 642513904 is about 25347.8579765628. The cubic root of 642513904 is about 862.9007439420.

The spelling of 642513904 in words is "six hundred forty-two million, five hundred thirteen thousand, nine hundred four".