18131331 has 8 divisors (see below), whose sum is σ = 24689664. Its totient is φ = 11830280.

The previous prime is 18131303. The next prime is 18131359. The reversal of 18131331 is 13313181.

It is an interprime number because it is at equal distance from previous prime (18131303) and next prime (18131359).

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 18131331 - 2⁷ = 18131203 is a prime.

It is a super-2 number, since 2×18131331² = 657490327663122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18131298 and 18131307.

It is not an unprimeable number, because it can be changed into a prime (18131371) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64155 + ... + 64436.

It is an arithmetic number, because the mean of its divisors is an integer number (3086208).

Almost surely, 2^18131331 is an apocalyptic number.

18131331 is a deficient number, since it is larger than the sum of its proper divisors (6558333).

18131331 is a wasteful number, since it uses less digits than its factorization.

18131331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128641.

The product of its digits is 216, while the sum is 21.

The square root of 18131331 is about 4258.0900648061. The cubic root of 18131331 is about 262.7099743998.

The spelling of 18131331 in words is "eighteen million, one hundred thirty-one thousand, three hundred thirty-one".