18539021 has 4 divisors (see below), whose sum is σ = 18598944. Its totient is φ = 18479100.

The previous prime is 18538997. The next prime is 18539051. The reversal of 18539021 is 12093581.

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 18539021 - 2⁶ = 18538957 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 (18539051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29495 + ... + 30116.

It is an arithmetic number, because the mean of its divisors is an integer number (4649736).

Almost surely, 2^18539021 is an apocalyptic number.

It is an amenable number.

18539021 is a deficient number, since it is larger than the sum of its proper divisors (59923).

18539021 is an equidigital number, since it uses as much as digits as its factorization.

18539021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59922.

The product of its (nonzero) digits is 2160, while the sum is 29.

The square root of 18539021 is about 4305.6963432179. The cubic root of 18539021 is about 264.6644429665.

The spelling of 18539021 in words is "eighteen million, five hundred thirty-nine thousand, twenty-one".