18392021 has 4 divisors (see below), whose sum is σ = 18985344. Its totient is φ = 17798700.

The previous prime is 18391991. The next prime is 18392027. The reversal of 18392021 is 12029381.

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 a cyclic number.

It is not a de Polignac number, because 18392021 - 2²² = 14197717 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 (18392027) 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, 296615 + ... + 296676.

It is an arithmetic number, because the mean of its divisors is an integer number (4746336).

Almost surely, 2^18392021 is an apocalyptic number.

It is an amenable number.

18392021 is a deficient number, since it is larger than the sum of its proper divisors (593323).

18392021 is an equidigital number, since it uses as much as digits as its factorization.

18392021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 593322.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 18392021 is about 4288.5919600727. The cubic root of 18392021 is about 263.9630582301.

The spelling of 18392021 in words is "eighteen million, three hundred ninety-two thousand, twenty-one".