18564681665 has 8 divisors (see below), whose sum is σ = 22284473280. Its totient is φ = 14847175152.

The previous prime is 18564681659. The next prime is 18564681677. The reversal of 18564681665 is 56618646581.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18564681665 - 2⁶ = 18564681601 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18564681665.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 553349 + ... + 585938.

It is an arithmetic number, because the mean of its divisors is an integer number (2785559160).

Almost surely, 2^18564681665 is an apocalyptic number.

It is an amenable number.

18564681665 is a deficient number, since it is larger than the sum of its proper divisors (3719791615).

18564681665 is a wasteful number, since it uses less digits than its factorization.

18564681665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1142551.

The product of its digits is 8294400, while the sum is 56.

The spelling of 18564681665 in words is "eighteen billion, five hundred sixty-four million, six hundred eighty-one thousand, six hundred sixty-five".