18320621 has 8 divisors (see below), whose sum is σ = 20325600. Its totient is φ = 16372240.

The previous prime is 18320609. The next prime is 18320629. The reversal of 18320621 is 12602381.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18320621 - 2¹⁰ = 18319597 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 (18320629) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13466 + ... + 14763.

It is an arithmetic number, because the mean of its divisors is an integer number (2540700).

Almost surely, 2^18320621 is an apocalyptic number.

18320621 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18320621 is a deficient number, since it is larger than the sum of its proper divisors (2004979).

18320621 is a wasteful number, since it uses less digits than its factorization.

18320621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28299.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 18320621 is about 4280.2594547527. The cubic root of 18320621 is about 263.6210366580.

The spelling of 18320621 in words is "eighteen million, three hundred twenty thousand, six hundred twenty-one".