18640864 has 24 divisors (see below), whose sum is σ = 40036248. Its totient is φ = 8472960.

The previous prime is 18640847. The next prime is 18640877. The reversal of 18640864 is 46804681.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 26127 + ... + 26830.

It is an arithmetic number, because the mean of its divisors is an integer number (1668177).

Almost surely, 2^18640864 is an apocalyptic number.

It is an amenable number.

18640864 is an abundant number, since it is smaller than the sum of its proper divisors (21395384).

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

18640864 is a wasteful number, since it uses less digits than its factorization.

18640864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52978 (or 52970 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 37.

The square root of 18640864 is about 4317.5066878929. The cubic root of 18640864 is about 265.1481976339.

The spelling of 18640864 in words is "eighteen million, six hundred forty thousand, eight hundred sixty-four".