18939219 has 32 divisors (see below), whose sum is σ = 29164800. Its totient is φ = 10834560.

The previous prime is 18939211. The next prime is 18939247. The reversal of 18939219 is 91293981.

18939219 = 1201² + 1202² + ... + 1213².

It is not a de Polignac number, because 18939219 - 2³ = 18939211 is a prime.

It is a super-2 number, since 2×18939219² = 717388032659922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18939211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 44992 + ... + 45410.

It is an arithmetic number, because the mean of its divisors is an integer number (911400).

Almost surely, 2^18939219 is an apocalyptic number.

18939219 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

18939219 is a deficient number, since it is larger than the sum of its proper divisors (10225581).

18939219 is a wasteful number, since it uses less digits than its factorization.

18939219 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 515.

The product of its digits is 34992, while the sum is 42.

The square root of 18939219 is about 4351.9212998399. The cubic root of 18939219 is about 266.5553203542. Note that the first 3 decimals are identical.

The spelling of 18939219 in words is "eighteen million, nine hundred thirty-nine thousand, two hundred nineteen".