18218111 has 16 divisors (see below), whose sum is σ = 19599360. Its totient is φ = 16904160.

The previous prime is 18218107. The next prime is 18218129. The reversal of 18218111 is 11181281.

It is not a de Polignac number, because 18218111 - 2² = 18218107 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18218191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 105221 + ... + 105393.

It is an arithmetic number, because the mean of its divisors is an integer number (1224960).

Almost surely, 2^18218111 is an apocalyptic number.

18218111 is a deficient number, since it is larger than the sum of its proper divisors (1381249).

18218111 is a wasteful number, since it uses less digits than its factorization.

18218111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 326.

The product of its digits is 128, while the sum is 23.

The square root of 18218111 is about 4268.2679156773. The cubic root of 18218111 is about 263.1284341399.

Adding to 18218111 its reverse (11181281), we get a palindrome (29399392).

The spelling of 18218111 in words is "eighteen million, two hundred eighteen thousand, one hundred eleven".