18168331 has 4 divisors (see below), whose sum is σ = 18187552. Its totient is φ = 18149112.

The previous prime is 18168299. The next prime is 18168343. The reversal of 18168331 is 13386181.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18168331 - 2⁵ = 18168299 is a prime.

It is a super-2 number, since 2×18168331² = 660176502651122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18168293 and 18168302.

It is not an unprimeable number, because it can be changed into a prime (18168361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8115 + ... + 10108.

It is an arithmetic number, because the mean of its divisors is an integer number (4546888).

Almost surely, 2^18168331 is an apocalyptic number.

18168331 is a deficient number, since it is larger than the sum of its proper divisors (19221).

18168331 is an equidigital number, since it uses as much as digits as its factorization.

18168331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19220.

The product of its digits is 3456, while the sum is 31.

The square root of 18168331 is about 4262.4325214600. The cubic root of 18168331 is about 262.8885541300. Note that the first 3 decimals are identical.

The spelling of 18168331 in words is "eighteen million, one hundred sixty-eight thousand, three hundred thirty-one".