18189 has 12 divisors (see below), whose sum is σ = 27456. Its totient is φ = 11592.

The previous prime is 18181. The next prime is 18191. The reversal of 18189 is 98181.

It is not a de Polignac number, because 18189 - 2³ = 18181 is a prime.

It is an alternating number because its digits alternate between odd and even.

Its product of digits (576) is a multiple of the sum of its prime factors (96).

18189 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 364 + ... + 410.

It is an arithmetic number, because the mean of its divisors is an integer number (2288).

2¹⁸¹⁸⁹ is an apocalyptic number.

It is an amenable number.

18189 is a deficient number, since it is larger than the sum of its proper divisors (9267).

18189 is a wasteful number, since it uses less digits than its factorization.

18189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96 (or 93 counting only the distinct ones).

The product of its digits is 576, while the sum is 27.

The square root of 18189 is about 134.8666007579. The cubic root of 18189 is about 26.2988207098.

The spelling of 18189 in words is "eighteen thousand, one hundred eighty-nine".