18875758021 has 4 divisors (see below), whose sum is σ = 18956770092. Its totient is φ = 18794745952.

The previous prime is 18875757991. The next prime is 18875758067. The reversal of 18875758021 is 12085757881.

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 6542544996 + 12333213025 = 80886^2 + 111055^2 .

It is a cyclic number.

It is not a de Polignac number, because 18875758021 - 2⁷ = 18875757893 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18875758021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18875758721) 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, 40505686 + ... + 40506151.

It is an arithmetic number, because the mean of its divisors is an integer number (4739192523).

Almost surely, 2^18875758021 is an apocalyptic number.

It is an amenable number.

18875758021 is a deficient number, since it is larger than the sum of its proper divisors (81012071).

18875758021 is an equidigital number, since it uses as much as digits as its factorization.

18875758021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81012070.

The product of its (nonzero) digits is 1254400, while the sum is 52.

The spelling of 18875758021 in words is "eighteen billion, eight hundred seventy-five million, seven hundred fifty-eight thousand, twenty-one".