18320689 has 4 divisors (see below), whose sum is σ = 18330624. Its totient is φ = 18310756.

The previous prime is 18320677. The next prime is 18320723. The reversal of 18320689 is 98602381.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 18320689 - 2¹⁷ = 18189617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18320609) 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, 1297 + ... + 6190.

It is an arithmetic number, because the mean of its divisors is an integer number (4582656).

Almost surely, 2^18320689 is an apocalyptic number.

It is an amenable number.

18320689 is a deficient number, since it is larger than the sum of its proper divisors (9935).

18320689 is an equidigital number, since it uses as much as digits as its factorization.

18320689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9934.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 18320689 is about 4280.2673981890. The cubic root of 18320689 is about 263.6213628153.

The spelling of 18320689 in words is "eighteen million, three hundred twenty thousand, six hundred eighty-nine".