18111331 has 12 divisors (see below), whose sum is σ = 21267840. Its totient is φ = 15377040.

The previous prime is 18111329. The next prime is 18111337. The reversal of 18111331 is 13311181.

It is not a de Polignac number, because 18111331 - 2¹ = 18111329 is a prime.

It is a super-2 number, since 2×18111331² = 656040621183122, 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 = 18111299 and 18111308.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18111337) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3646 + ... + 7036.

It is an arithmetic number, because the mean of its divisors is an integer number (1772320).

Almost surely, 2^18111331 is an apocalyptic number.

18111331 is a deficient number, since it is larger than the sum of its proper divisors (3156509).

18111331 is a wasteful number, since it uses less digits than its factorization.

18111331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3514 (or 3507 counting only the distinct ones).

The product of its digits is 72, while the sum is 19.

The square root of 18111331 is about 4255.7409460633. The cubic root of 18111331 is about 262.6133436454.

The spelling of 18111331 in words is "eighteen million, one hundred eleven thousand, three hundred thirty-one".