18231 has 8 divisors (see below), whose sum is σ = 24960. Its totient is φ = 11832.

The previous prime is 18229. The next prime is 18233. The reversal of 18231 is 13281.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18229) and next prime (18233).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18231 - 2¹ = 18229 is a prime.

It is a super-2 number, since 2×18231² = 664738722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18233) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 126 + ... + 228.

It is an arithmetic number, because the mean of its divisors is an integer number (3120).

2¹⁸²³¹ is an apocalyptic number.

18231 is a deficient number, since it is larger than the sum of its proper divisors (6729).

18231 is a wasteful number, since it uses less digits than its factorization.

18231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165.

The product of its digits is 48, while the sum is 15.

The square root of 18231 is about 135.0222203935. The cubic root of 18231 is about 26.3190472458.

Subtracting from 18231 its reverse (13281), we obtain a triangular number (4950 = T₉₉).

The spelling of 18231 in words is "eighteen thousand, two hundred thirty-one".