18568404521 has 12 divisors (see below), whose sum is σ = 19196390016. Its totient is φ = 17960357160.

The previous prime is 18568404509. The next prime is 18568404541. The reversal of 18568404521 is 12540486581.

It is a de Polignac number, because none of the positive numbers 2^k-18568404521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18568404541) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2655596 + ... + 2662578.

It is an arithmetic number, because the mean of its divisors is an integer number (1599699168).

Almost surely, 2^18568404521 is an apocalyptic number.

It is an amenable number.

18568404521 is a deficient number, since it is larger than the sum of its proper divisors (627985495).

18568404521 is an equidigital number, since it uses as much as digits as its factorization.

18568404521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9812 (or 9781 counting only the distinct ones).

The product of its (nonzero) digits is 307200, while the sum is 44.

The spelling of 18568404521 in words is "eighteen billion, five hundred sixty-eight million, four hundred four thousand, five hundred twenty-one".