18022112021 has 4 divisors (see below), whose sum is σ = 18181599852. Its totient is φ = 17862624192.

The previous prime is 18022112011. The next prime is 18022112039. The reversal of 18022112021 is 12021122081.

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

It can be written as a sum of positive squares in 2 ways, for example, as 699867025 + 17322244996 = 26455^2 + 131614^2 .

It is a cyclic number.

It is not a de Polignac number, because 18022112021 - 2²² = 18017917717 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18022111984 and 18022112002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18022112011) 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, 79743746 + ... + 79743971.

It is an arithmetic number, because the mean of its divisors is an integer number (4545399963).

Almost surely, 2^18022112021 is an apocalyptic number.

It is an amenable number.

18022112021 is a deficient number, since it is larger than the sum of its proper divisors (159487831).

18022112021 is a wasteful number, since it uses less digits than its factorization.

18022112021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159487830.

The product of its (nonzero) digits is 128, while the sum is 20.

The spelling of 18022112021 in words is "eighteen billion, twenty-two million, one hundred twelve thousand, twenty-one".