18419989 has 4 divisors (see below), whose sum is σ = 21051424. Its totient is φ = 15788556.

The previous prime is 18419981. The next prime is 18420007. The reversal of 18419989 is 98991481.

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 18419989 - 2³ = 18419981 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 (18419981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1315707 + ... + 1315720.

It is an arithmetic number, because the mean of its divisors is an integer number (5262856).

Almost surely, 2^18419989 is an apocalyptic number.

It is an amenable number.

18419989 is a deficient number, since it is larger than the sum of its proper divisors (2631435).

18419989 is an equidigital number, since it uses as much as digits as its factorization.

18419989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2631434.

The product of its digits is 186624, while the sum is 49.

The square root of 18419989 is about 4291.8514652770. The cubic root of 18419989 is about 264.0967897700.

The spelling of 18419989 in words is "eighteen million, four hundred nineteen thousand, nine hundred eighty-nine".