18328231 has 2 divisors, whose sum is σ = 18328232. Its totient is φ = 18328230.

The previous prime is 18328201. The next prime is 18328249. The reversal of 18328231 is 13282381.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18328231 - 2⁵ = 18328199 is a prime.

It is a super-2 number, since 2×18328231² = 671848103178722, which contains 22 as substring.

It is equal to p_1170991 and since 18328231 and 1170991 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18328231.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18328201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9164115 + 9164116.

It is an arithmetic number, because the mean of its divisors is an integer number (9164116).

Almost surely, 2^18328231 is an apocalyptic number.

18328231 is a deficient number, since it is larger than the sum of its proper divisors (1).

18328231 is an equidigital number, since it uses as much as digits as its factorization.

18328231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2304, while the sum is 28.

The square root of 18328231 is about 4281.1483272599. The cubic root of 18328231 is about 263.6575324803.

The spelling of 18328231 in words is "eighteen million, three hundred twenty-eight thousand, two hundred thirty-one".