18166566 has 16 divisors (see below), whose sum is σ = 39636288. Its totient is φ = 5505000.

The previous prime is 18166549. The next prime is 18166579. The reversal of 18166566 is 66566181.

It is a Curzon number.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 137560 + ... + 137691.

It is an arithmetic number, because the mean of its divisors is an integer number (2477268).

Almost surely, 2^18166566 is an apocalyptic number.

18166566 is an abundant number, since it is smaller than the sum of its proper divisors (21469722).

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

18166566 is a wasteful number, since it uses less digits than its factorization.

18166566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275267.

The product of its digits is 51840, while the sum is 39.

The square root of 18166566 is about 4262.2254750306. The cubic root of 18166566 is about 262.8800409040.

The spelling of 18166566 in words is "eighteen million, one hundred sixty-six thousand, five hundred sixty-six".