18839218 has 4 divisors (see below), whose sum is σ = 28258830. Its totient is φ = 9419608.

The previous prime is 18839207. The next prime is 18839237. The reversal of 18839218 is 81293881.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81293881 = 17 ⋅4781993.

It can be written as a sum of positive squares in only one way, i.e., 12723489 + 6115729 = 3567^2 + 2473^2 .

It is a super-2 number, since 2×18839218² = 709832269703048, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4709803 + ... + 4709806.

Almost surely, 2^18839218 is an apocalyptic number.

18839218 is a deficient number, since it is larger than the sum of its proper divisors (9419612).

18839218 is an equidigital number, since it uses as much as digits as its factorization.

18839218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9419611.

The product of its digits is 27648, while the sum is 40.

The square root of 18839218 is about 4340.4168002624. The cubic root of 18839218 is about 266.0853458214.

The spelling of 18839218 in words is "eighteen million, eight hundred thirty-nine thousand, two hundred eighteen".