18189172 has 12 divisors (see below), whose sum is σ = 32571616. Its totient is φ = 8883000.

The previous prime is 18189161. The next prime is 18189179. The reversal of 18189172 is 27198181.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18189179) 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, 52704 + ... + 53047.

Almost surely, 2^18189172 is an apocalyptic number.

It is an amenable number.

18189172 is a deficient number, since it is larger than the sum of its proper divisors (14382444).

18189172 is a wasteful number, since it uses less digits than its factorization.

18189172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105798 (or 105796 counting only the distinct ones).

The product of its digits is 8064, while the sum is 37.

The square root of 18189172 is about 4264.8765515546. The cubic root of 18189172 is about 262.9890360574.

Subtracting 18189172 from its reverse (27198181), we obtain a palindrome (9009009).

The spelling of 18189172 in words is "eighteen million, one hundred eighty-nine thousand, one hundred seventy-two".