18118566 has 84 divisors (see below), whose sum is σ = 44292732. Its totient is φ = 5552064.

The previous prime is 18118553. The next prime is 18118589. The reversal of 18118566 is 66581181.

18118566 is a `hidden beast` number, since 1 + 81 + 18 + 566 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 18118566.

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 41 ways as a sum of consecutive naturals, for example, 421341 + ... + 421383.

Almost surely, 2^18118566 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18118566, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22146366).

18118566 is an abundant number, since it is smaller than the sum of its proper divisors (26174166).

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

18118566 is an equidigital number, since it uses as much as digits as its factorization.

18118566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97 (or 65 counting only the distinct ones).

The product of its digits is 11520, while the sum is 36.

The square root of 18118566 is about 4256.5908894325. The cubic root of 18118566 is about 262.6483080294.

The spelling of 18118566 in words is "eighteen million, one hundred eighteen thousand, five hundred sixty-six".