18390564 has 60 divisors (see below), whose sum is σ = 49654528. Its totient is φ = 5929200.

The previous prime is 18390563. The next prime is 18390569. The reversal of 18390564 is 46509381.

18390564 is a `hidden beast` number, since 1 + 8 + 3 + 90 + 564 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (18390563) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 9129 + ... + 10959.

Almost surely, 2^18390564 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18390564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24827264).

18390564 is an abundant number, since it is smaller than the sum of its proper divisors (31263964).

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

18390564 is a wasteful number, since it uses less digits than its factorization.

18390564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1878 (or 1867 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 18390564 is about 4288.4220874350. The cubic root of 18390564 is about 263.9560877376.

The spelling of 18390564 in words is "eighteen million, three hundred ninety thousand, five hundred sixty-four".