642308556 has 12 divisors (see below), whose sum is σ = 1498719992. Its totient is φ = 214102848.

The previous prime is 642308507. The next prime is 642308657. The reversal of 642308556 is 655803246.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×642308556² = 825120562221610272, which contains 22 as substring.

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, 26762845 + ... + 26762868.

Almost surely, 2^642308556 is an apocalyptic number.

It is an amenable number.

642308556 is an abundant number, since it is smaller than the sum of its proper divisors (856411436).

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

642308556 is a wasteful number, since it uses less digits than its factorization.

642308556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53525720 (or 53525718 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 39.

The square root of 642308556 is about 25343.8070541898. The cubic root of 642308556 is about 862.8088062052.

The spelling of 642308556 in words is "six hundred forty-two million, three hundred eight thousand, five hundred fifty-six".