18155784651664 has 80 divisors (see below), whose sum is σ = 38917977375744. Its totient is φ = 8135817782400.

The previous prime is 18155784651629. The next prime is 18155784651679. The reversal of 18155784651664 is 46615648755181.

It is a self number, because there is not a number n which added to its sum of digits gives 18155784651664.

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, 210426997 + ... + 210513259.

Almost surely, 2^{18155784651664} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18155784651664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19458988687872).

18155784651664 is an abundant number, since it is smaller than the sum of its proper divisors (20762192724080).

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

18155784651664 is a wasteful number, since it uses less digits than its factorization.

18155784651664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103196 (or 103190 counting only the distinct ones).

The product of its digits is 193536000, while the sum is 67.

The spelling of 18155784651664 in words is "eighteen trillion, one hundred fifty-five billion, seven hundred eighty-four million, six hundred fifty-one thousand, six hundred sixty-four".