18640564 has 12 divisors (see below), whose sum is σ = 32657184. Its totient is φ = 9309944.

The previous prime is 18640561. The next prime is 18640621. The reversal of 18640564 is 46504681.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18640561) 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 3 ways as a sum of consecutive naturals, for example, 2649 + ... + 6655.

It is an arithmetic number, because the mean of its divisors is an integer number (2721432).

Almost surely, 2^18640564 is an apocalyptic number.

It is an amenable number.

18640564 is a deficient number, since it is larger than the sum of its proper divisors (14016620).

18640564 is a wasteful number, since it uses less digits than its factorization.

18640564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5174 (or 5172 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 34.

The square root of 18640564 is about 4317.4719454792. The cubic root of 18640564 is about 265.1467752234.

The spelling of 18640564 in words is "eighteen million, six hundred forty thousand, five hundred sixty-four".