18111216 has 40 divisors (see below), whose sum is σ = 47171584. Its totient is φ = 5987520.

The previous prime is 18111187. The next prime is 18111229. The reversal of 18111216 is 61211181.

It is a happy number.

It is a super-2 number, since 2×18111216² = 656032289997312, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 18111192 and 18111201.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 4611 + ... + 7581.

Almost surely, 2^18111216 is an apocalyptic number.

18111216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

18111216 is an abundant number, since it is smaller than the sum of its proper divisors (29060368).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18111216 is a wasteful number, since it uses less digits than its factorization.

18111216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3109 (or 3103 counting only the distinct ones).

The product of its digits is 96, while the sum is 21.

The square root of 18111216 is about 4255.7274348811. The cubic root of 18111216 is about 262.6127878129.

Adding to 18111216 its reverse (61211181), we get a palindrome (79322397).

The spelling of 18111216 in words is "eighteen million, one hundred eleven thousand, two hundred sixteen".