18219155 has 16 divisors (see below), whose sum is σ = 23385024. Its totient is φ = 13578240.

The previous prime is 18219139. The next prime is 18219161. The reversal of 18219155 is 55191281.

It is not a de Polignac number, because 18219155 - 2⁴ = 18219139 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7715 + ... + 9795.

It is an arithmetic number, because the mean of its divisors is an integer number (1461564).

Almost surely, 2^18219155 is an apocalyptic number.

18219155 is a deficient number, since it is larger than the sum of its proper divisors (5165869).

18219155 is a wasteful number, since it uses less digits than its factorization.

18219155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2206.

The product of its digits is 3600, while the sum is 32.

The square root of 18219155 is about 4268.3902117777. The cubic root of 18219155 is about 263.1334602892.

The spelling of 18219155 in words is "eighteen million, two hundred nineteen thousand, one hundred fifty-five".