18209331 has 36 divisors (see below), whose sum is σ = 30908592. Its totient is φ = 10299744.

The previous prime is 18209309. The next prime is 18209333. The reversal of 18209331 is 13390281.

It is not a de Polignac number, because 18209331 - 2⁷ = 18209203 is a prime.

It is a super-2 number, since 2×18209331² = 663159470935122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18209295 and 18209304.

It is not an unprimeable number, because it can be changed into a prime (18209333) 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 35 ways as a sum of consecutive naturals, for example, 69106 + ... + 69368.

It is an arithmetic number, because the mean of its divisors is an integer number (858572).

Almost surely, 2^18209331 is an apocalyptic number.

18209331 is a deficient number, since it is larger than the sum of its proper divisors (12699261).

18209331 is a wasteful number, since it uses less digits than its factorization.

18209331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440 (or 430 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 18209331 is about 4267.2392714728. The cubic root of 18209331 is about 263.0861568170.

The spelling of 18209331 in words is "eighteen million, two hundred nine thousand, three hundred thirty-one".