18115816549944 has 128 divisors (see below), whose sum is σ = 46629698068800. Its totient is φ = 5860741386240.

The previous prime is 18115816549933. The next prime is 18115816549991. The reversal of 18115816549944 is 44994561851181.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1804898494 + ... + 1804908530.

Almost surely, 2^{18115816549944} 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 18115816549944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23314849034400).

18115816549944 is an abundant number, since it is smaller than the sum of its proper divisors (28513881518856).

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

18115816549944 is a wasteful number, since it uses less digits than its factorization.

18115816549944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14953 (or 14949 counting only the distinct ones).

The product of its digits is 49766400, while the sum is 66.

The spelling of 18115816549944 in words is "eighteen trillion, one hundred fifteen billion, eight hundred sixteen million, five hundred forty-nine thousand, nine hundred forty-four".