18087231 has 8 divisors (see below), whose sum is σ = 24159744. Its totient is φ = 12036440.

The previous prime is 18087227. The next prime is 18087241. The reversal of 18087231 is 13278081.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18087231 - 2² = 18087227 is a prime.

It is a super-2 number, since 2×18087231² = 654295850494722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18087211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3375 + ... + 6896.

It is an arithmetic number, because the mean of its divisors is an integer number (3019968).

Almost surely, 2^18087231 is an apocalyptic number.

18087231 is a deficient number, since it is larger than the sum of its proper divisors (6072513).

18087231 is a wasteful number, since it uses less digits than its factorization.

18087231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10861.

The product of its (nonzero) digits is 2688, while the sum is 30.

The square root of 18087231 is about 4252.9085341681. The cubic root of 18087231 is about 262.4968090315.

The spelling of 18087231 in words is "eighteen million, eighty-seven thousand, two hundred thirty-one".