18189331 has 2 divisors, whose sum is σ = 18189332. Its totient is φ = 18189330.

The previous prime is 18189323. The next prime is 18189341. The reversal of 18189331 is 13398181.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18189331 - 2³ = 18189323 is a prime.

It is a super-2 number, since 2×18189331² = 661703524455122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18189341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9094665 + 9094666.

It is an arithmetic number, because the mean of its divisors is an integer number (9094666).

Almost surely, 2^18189331 is an apocalyptic number.

18189331 is a deficient number, since it is larger than the sum of its proper divisors (1).

18189331 is an equidigital number, since it uses as much as digits as its factorization.

18189331 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 34.

The square root of 18189331 is about 4264.8951921472. The cubic root of 18189331 is about 262.9898023582.

The spelling of 18189331 in words is "eighteen million, one hundred eighty-nine thousand, three hundred thirty-one".