18242185021 has 4 divisors (see below), whose sum is σ = 18253116700. Its totient is φ = 18231253344.

The previous prime is 18242185009. The next prime is 18242185033. The reversal of 18242185021 is 12058124281.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (18242185009) and next prime (18242185033).

It can be written as a sum of positive squares in 2 ways, for example, as 5695720900 + 12546464121 = 75470^2 + 112011^2 .

It is a cyclic number.

It is not a de Polignac number, because 18242185021 - 2⁷ = 18242184893 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 (18242185061) 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, 5463336 + ... + 5466673.

It is an arithmetic number, because the mean of its divisors is an integer number (4563279175).

Almost surely, 2^18242185021 is an apocalyptic number.

It is an amenable number.

18242185021 is a deficient number, since it is larger than the sum of its proper divisors (10931679).

18242185021 is a wasteful number, since it uses less digits than its factorization.

18242185021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10931678.

The product of its (nonzero) digits is 10240, while the sum is 34.

The spelling of 18242185021 in words is "eighteen billion, two hundred forty-two million, one hundred eighty-five thousand, twenty-one".