18605231 has 2 divisors, whose sum is σ = 18605232. Its totient is φ = 18605230.

The previous prime is 18605227. The next prime is 18605233. The reversal of 18605231 is 13250681.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18605231 - 2² = 18605227 is a prime.

It is a super-2 number, since 2×18605231² = 692309241126722, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 18605233, 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 18605231.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18605233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9302615 + 9302616.

It is an arithmetic number, because the mean of its divisors is an integer number (9302616).

Almost surely, 2^18605231 is an apocalyptic number.

18605231 is a deficient number, since it is larger than the sum of its proper divisors (1).

18605231 is an equidigital number, since it uses as much as digits as its factorization.

18605231 is an odious number, because the sum of its binary digits is odd.

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

The square root of 18605231 is about 4313.3781424772. The cubic root of 18605231 is about 264.9791415884.

The spelling of 18605231 in words is "eighteen million, six hundred five thousand, two hundred thirty-one".