18722219 has 4 divisors (see below), whose sum is σ = 19823544. Its totient is φ = 17620896.

The previous prime is 18722191. The next prime is 18722267. The reversal of 18722219 is 91222781.

It is a happy number.

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 18722219 - 2¹² = 18718123 is a prime.

It is a super-2 number, since 2×18722219² = 701042968567922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18742219) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 550637 + ... + 550670.

It is an arithmetic number, because the mean of its divisors is an integer number (4955886).

Almost surely, 2^18722219 is an apocalyptic number.

18722219 is a deficient number, since it is larger than the sum of its proper divisors (1101325).

18722219 is a wasteful number, since it uses less digits than its factorization.

18722219 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1101324.

The product of its digits is 4032, while the sum is 32.

The square root of 18722219 is about 4326.9179562363. The cubic root of 18722219 is about 265.5333698066.

The spelling of 18722219 in words is "eighteen million, seven hundred twenty-two thousand, two hundred nineteen".