18506231 has 2 divisors, whose sum is σ = 18506232. Its totient is φ = 18506230.

The previous prime is 18506227. The next prime is 18506233. The reversal of 18506231 is 13260581.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18506231 - 2² = 18506227 is a prime.

It is a super-2 number, since 2×18506231² = 684961171650722, which contains 22 as substring.

Together with 18506233, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18506231.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18506233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9253115 + 9253116.

It is an arithmetic number, because the mean of its divisors is an integer number (9253116).

Almost surely, 2^18506231 is an apocalyptic number.

18506231 is a deficient number, since it is larger than the sum of its proper divisors (1).

18506231 is an equidigital number, since it uses as much as digits as its factorization.

18506231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 18506231 is about 4301.8869115773. The cubic root of 18506231 is about 264.5083133882.

The spelling of 18506231 in words is "eighteen million, five hundred six thousand, two hundred thirty-one".