18565649816 has 64 divisors (see below), whose sum is σ = 44340825600. Its totient is φ = 7094518272.

The previous prime is 18565649801. The next prime is 18565649863. The reversal of 18565649816 is 61894656581.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 495116 + ... + 531291.

It is an arithmetic number, because the mean of its divisors is an integer number (692825400).

Almost surely, 2^18565649816 is an apocalyptic number.

It is an amenable number.

18565649816 is an abundant number, since it is smaller than the sum of its proper divisors (25775175784).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18565649816 is a wasteful number, since it uses less digits than its factorization.

18565649816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1026456 (or 1026452 counting only the distinct ones).

The product of its digits is 12441600, while the sum is 59.

The spelling of 18565649816 in words is "eighteen billion, five hundred sixty-five million, six hundred forty-nine thousand, eight hundred sixteen".