18918999 has 48 divisors (see below), whose sum is σ = 31449600. Its totient is φ = 10857600.

The previous prime is 18918983. The next prime is 18919007. The reversal of 18918999 is 99981981.

It is not a de Polignac number, because 18918999 - 2⁴ = 18918983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18918919) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 239442 + ... + 239520.

It is an arithmetic number, because the mean of its divisors is an integer number (655200).

Almost surely, 2^18918999 is an apocalyptic number.

18918999 is a deficient number, since it is larger than the sum of its proper divisors (12530601).

18918999 is a wasteful number, since it uses less digits than its factorization.

18918999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196 (or 193 counting only the distinct ones).

The product of its digits is 419904, while the sum is 54.

The square root of 18918999 is about 4349.5975675917. The cubic root of 18918999 is about 266.4604261245.

The spelling of 18918999 in words is "eighteen million, nine hundred eighteen thousand, nine hundred ninety-nine".