18081231 has 16 divisors (see below), whose sum is σ = 27681024. Its totient is φ = 10283904.

The previous prime is 18081227. The next prime is 18081233. The reversal of 18081231 is 13218081.

It is not a de Polignac number, because 18081231 - 2² = 18081227 is a prime.

It is a super-2 number, since 2×18081231² = 653861828950722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18081233) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2871 + ... + 6663.

It is an arithmetic number, because the mean of its divisors is an integer number (1730064).

Almost surely, 2^18081231 is an apocalyptic number.

18081231 is a deficient number, since it is larger than the sum of its proper divisors (9599793).

18081231 is a wasteful number, since it uses less digits than its factorization.

18081231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4030.

The product of its (nonzero) digits is 384, while the sum is 24.

The square root of 18081231 is about 4252.2030760536. The cubic root of 18081231 is about 262.4677801724.

The spelling of 18081231 in words is "eighteen million, eighty-one thousand, two hundred thirty-one".