18706231 has 2 divisors, whose sum is σ = 18706232. Its totient is φ = 18706230.

The previous prime is 18706213. The next prime is 18706267. The reversal of 18706231 is 13260781.

Together with previous prime (18706213) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18706231 - 2⁹ = 18705719 is a prime.

It is a super-2 number, since 2×18706231² = 699846156450722, 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 18706231.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18707231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9353115 + 9353116.

It is an arithmetic number, because the mean of its divisors is an integer number (9353116).

Almost surely, 2^18706231 is an apocalyptic number.

18706231 is a deficient number, since it is larger than the sum of its proper divisors (1).

18706231 is an equidigital number, since it uses as much as digits as its factorization.

18706231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 18706231 is about 4325.0700572361. The cubic root of 18706231 is about 265.4577634457.

The spelling of 18706231 in words is "eighteen million, seven hundred six thousand, two hundred thirty-one".