642918188 has 24 divisors (see below), whose sum is σ = 1238658960. Its totient is φ = 289552320.

The previous prime is 642918173. The next prime is 642918191. The reversal of 642918188 is 881819246.

It is a happy number.

It is a super-2 number, since 2×642918188² = 826687592922406688, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62231 + ... + 71822.

It is an arithmetic number, because the mean of its divisors is an integer number (51610790).

Almost surely, 2^642918188 is an apocalyptic number.

It is an amenable number.

642918188 is a deficient number, since it is larger than the sum of its proper divisors (595740772).

642918188 is a wasteful number, since it uses less digits than its factorization.

642918188 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134177 (or 134175 counting only the distinct ones).

The product of its digits is 221184, while the sum is 47.

The square root of 642918188 is about 25355.8314397300. The cubic root of 642918188 is about 863.0816914246.

The spelling of 642918188 in words is "six hundred forty-two million, nine hundred eighteen thousand, one hundred eighty-eight".