18159331 has 2 divisors, whose sum is σ = 18159332. Its totient is φ = 18159330.

The previous prime is 18159313. The next prime is 18159353. The reversal of 18159331 is 13395181.

Together with previous prime (18159313) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is an emirp because it is prime and its reverse (13395181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18159331 - 2⁵ = 18159299 is a prime.

It is a super-2 number, since 2×18159331² = 659522604735122, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 18159293 and 18159302.

It is not a weakly prime, because it can be changed into another prime (18159301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9079665 + 9079666.

It is an arithmetic number, because the mean of its divisors is an integer number (9079666).

Almost surely, 2^18159331 is an apocalyptic number.

18159331 is a deficient number, since it is larger than the sum of its proper divisors (1).

18159331 is an equidigital number, since it uses as much as digits as its factorization.

18159331 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3240, while the sum is 31.

The square root of 18159331 is about 4261.3766554953. The cubic root of 18159331 is about 262.8451381484.

The spelling of 18159331 in words is "eighteen million, one hundred fifty-nine thousand, three hundred thirty-one".