18164556 has 72 divisors (see below), whose sum is σ = 48222720. Its totient is φ = 5757696.

The previous prime is 18164539. The next prime is 18164561. The reversal of 18164556 is 65546181.

18164556 is a `hidden beast` number, since 1 + 8 + 1 + 645 + 5 + 6 = 666.

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

It is a self number, because there is not a number n which added to its sum of digits gives 18164556.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 132520 + ... + 132656.

It is an arithmetic number, because the mean of its divisors is an integer number (669760).

Almost surely, 2^18164556 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 18164556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24111360).

18164556 is an abundant number, since it is smaller than the sum of its proper divisors (30058164).

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

18164556 is a wasteful number, since it uses less digits than its factorization.

18164556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303 (or 298 counting only the distinct ones).

The product of its digits is 28800, while the sum is 36.

The square root of 18164556 is about 4261.9896761958. The cubic root of 18164556 is about 262.8703452839.

The spelling of 18164556 in words is "eighteen million, one hundred sixty-four thousand, five hundred fifty-six".