18219219 has 16 divisors (see below), whose sum is σ = 24775968. Its totient is φ = 11907072.

The previous prime is 18219203. The next prime is 18219251. The reversal of 18219219 is 91291281.

It is not a de Polignac number, because 18219219 - 2⁴ = 18219203 is a prime.

It is a super-2 number, since 2×18219219² = 663879881939922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18219219.

It is not an unprimeable number, because it can be changed into a prime (18219269) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39639 + ... + 40095.

It is an arithmetic number, because the mean of its divisors is an integer number (1548498).

Almost surely, 2^18219219 is an apocalyptic number.

18219219 is a deficient number, since it is larger than the sum of its proper divisors (6556749).

18219219 is a wasteful number, since it uses less digits than its factorization.

18219219 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 694.

The product of its digits is 2592, while the sum is 33.

The square root of 18219219 is about 4268.3977087427. The cubic root of 18219219 is about 263.1337683994.

The spelling of 18219219 in words is "eighteen million, two hundred nineteen thousand, two hundred nineteen".