18418989 has 4 divisors (see below), whose sum is σ = 24558656. Its totient is φ = 12279324.

The previous prime is 18418979. The next prime is 18419017. The reversal of 18418989 is 98981481.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 18418989 - 2⁵ = 18418957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18418969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3069829 + ... + 3069834.

It is an arithmetic number, because the mean of its divisors is an integer number (6139664).

Almost surely, 2^18418989 is an apocalyptic number.

It is an amenable number.

18418989 is a deficient number, since it is larger than the sum of its proper divisors (6139667).

18418989 is an equidigital number, since it uses as much as digits as its factorization.

18418989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6139666.

The product of its digits is 165888, while the sum is 48.

The square root of 18418989 is about 4291.7349638579. The cubic root of 18418989 is about 264.0920105133.

The spelling of 18418989 in words is "eighteen million, four hundred eighteen thousand, nine hundred eighty-nine".