18031231 has 8 divisors (see below), whose sum is σ = 18381600. Its totient is φ = 17683680.

The previous prime is 18031217. The next prime is 18031249. The reversal of 18031231 is 13213081.

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 18031231 - 2⁵ = 18031199 is a prime.

It is a super-2 number, since 2×18031231² = 650250582750722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18031199 and 18031208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18035231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15705 + ... + 16813.

It is an arithmetic number, because the mean of its divisors is an integer number (2297700).

Almost surely, 2^18031231 is an apocalyptic number.

18031231 is a deficient number, since it is larger than the sum of its proper divisors (350369).

18031231 is a wasteful number, since it uses less digits than its factorization.

18031231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1409.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 18031231 is about 4246.3197006349. The cubic root of 18031231 is about 262.2256229077.

The spelling of 18031231 in words is "eighteen million, thirty-one thousand, two hundred thirty-one".