18818919 has 16 divisors (see below), whose sum is σ = 31863040. Its totient is φ = 10753560.

The previous prime is 18818909. The next prime is 18818923. The reversal of 18818919 is 91981881.

It is not a de Polignac number, because 18818919 - 2⁷ = 18818791 is a prime.

It is a super-2 number, since 2×18818919² = 708303424657122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18818909) 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, 49597 + ... + 49974.

It is an arithmetic number, because the mean of its divisors is an integer number (1991440).

Almost surely, 2^18818919 is an apocalyptic number.

18818919 is a deficient number, since it is larger than the sum of its proper divisors (13044121).

18818919 is an equidigital number, since it uses as much as digits as its factorization.

18818919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99587 (or 99581 counting only the distinct ones).

The product of its digits is 41472, while the sum is 45.

The square root of 18818919 is about 4338.0778001322. The cubic root of 18818919 is about 265.9897437016.

The spelling of 18818919 in words is "eighteen million, eight hundred eighteen thousand, nine hundred nineteen".