642656044 has 12 divisors (see below), whose sum is σ = 1125603864. Its totient is φ = 321054944.

The previous prime is 642656039. The next prime is 642656059. The reversal of 642656044 is 440656246.

It is a junction number, because it is equal to n+sod(n) for n = 642655994 and 642656012.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 62929 + ... + 72424.

It is an arithmetic number, because the mean of its divisors is an integer number (93800322).

Almost surely, 2^642656044 is an apocalyptic number.

It is an amenable number.

642656044 is a deficient number, since it is larger than the sum of its proper divisors (482947820).

642656044 is a wasteful number, since it uses less digits than its factorization.

642656044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136544 (or 136542 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 37.

The square root of 642656044 is about 25350.6616087234. The cubic root of 642656044 is about 862.9643709273.

The spelling of 642656044 in words is "six hundred forty-two million, six hundred fifty-six thousand, forty-four".