18204328661 has 4 divisors (see below), whose sum is σ = 18208034400. Its totient is φ = 18200622924.

The previous prime is 18204328657. The next prime is 18204328669. The reversal of 18204328661 is 16682340281.

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 18204328661 - 2² = 18204328657 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 (18204328669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1845491 + ... + 1855328.

It is an arithmetic number, because the mean of its divisors is an integer number (4552008600).

Almost surely, 2^18204328661 is an apocalyptic number.

It is an amenable number.

18204328661 is a deficient number, since it is larger than the sum of its proper divisors (3705739).

18204328661 is an equidigital number, since it uses as much as digits as its factorization.

18204328661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3705738.

The product of its (nonzero) digits is 110592, while the sum is 41.

The spelling of 18204328661 in words is "eighteen billion, two hundred four million, three hundred twenty-eight thousand, six hundred sixty-one".