18373989 has 4 divisors (see below), whose sum is σ = 24498656. Its totient is φ = 12249324.

The previous prime is 18373981. The next prime is 18374011. The reversal of 18373989 is 98937381.

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 18373989 - 2³ = 18373981 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 (18373981) 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, 3062329 + ... + 3062334.

It is an arithmetic number, because the mean of its divisors is an integer number (6124664).

Almost surely, 2^18373989 is an apocalyptic number.

It is an amenable number.

18373989 is a deficient number, since it is larger than the sum of its proper divisors (6124667).

18373989 is an equidigital number, since it uses as much as digits as its factorization.

18373989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6124666.

The product of its digits is 326592, while the sum is 48.

The square root of 18373989 is about 4286.4891228137. The cubic root of 18373989 is about 263.8767646819.

The spelling of 18373989 in words is "eighteen million, three hundred seventy-three thousand, nine hundred eighty-nine".