18989564 has 12 divisors (see below), whose sum is σ = 36252888. Its totient is φ = 8631600.

The previous prime is 18989543. The next prime is 18989567. The reversal of 18989564 is 46598981.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18989567) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 215747 + ... + 215834.

It is an arithmetic number, because the mean of its divisors is an integer number (3021074).

Almost surely, 2^18989564 is an apocalyptic number.

It is an amenable number.

18989564 is a deficient number, since it is larger than the sum of its proper divisors (17263324).

18989564 is a wasteful number, since it uses less digits than its factorization.

18989564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431596 (or 431594 counting only the distinct ones).

The product of its digits is 622080, while the sum is 50.

The square root of 18989564 is about 4357.7016878166. The cubic root of 18989564 is about 266.7913007675.

The spelling of 18989564 in words is "eighteen million, nine hundred eighty-nine thousand, five hundred sixty-four".