18664857 has 16 divisors (see below), whose sum is σ = 27720000. Its totient is φ = 12412512.

The previous prime is 18664843. The next prime is 18664873. The reversal of 18664857 is 75846681.

It is a happy number.

It is not a de Polignac number, because 18664857 - 2⁷ = 18664729 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18664057) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 17269 + ... + 18317.

It is an arithmetic number, because the mean of its divisors is an integer number (1732500).

Almost surely, 2^18664857 is an apocalyptic number.

It is an amenable number.

18664857 is a deficient number, since it is larger than the sum of its proper divisors (9055143).

18664857 is a wasteful number, since it uses less digits than its factorization.

18664857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1717 (or 1711 counting only the distinct ones).

The product of its digits is 322560, while the sum is 45.

The square root of 18664857 is about 4320.2843656408. The cubic root of 18664857 is about 265.2619079075.

The spelling of 18664857 in words is "eighteen million, six hundred sixty-four thousand, eight hundred fifty-seven".