18319231 has 16 divisors (see below), whose sum is σ = 21437440. Its totient is φ = 15331680.

The previous prime is 18319219. The next prime is 18319241. The reversal of 18319231 is 13291381.

It is not a de Polignac number, because 18319231 - 2⁵ = 18319199 is a prime.

It is a super-2 number, since 2×18319231² = 671188448862722, 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 18319231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18319241) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 86716 + ... + 86926.

It is an arithmetic number, because the mean of its divisors is an integer number (1339840).

Almost surely, 2^18319231 is an apocalyptic number.

18319231 is a deficient number, since it is larger than the sum of its proper divisors (3118209).

18319231 is a wasteful number, since it uses less digits than its factorization.

18319231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 454.

The product of its digits is 1296, while the sum is 28.

The square root of 18319231 is about 4280.0970783383. The cubic root of 18319231 is about 263.6143694439.

The spelling of 18319231 in words is "eighteen million, three hundred nineteen thousand, two hundred thirty-one".