18981886440016 has 20 divisors (see below), whose sum is σ = 37156553485492. Its totient is φ = 9393098443776.

The previous prime is 18981886440007. The next prime is 18981886440029. The reversal of 18981886440016 is 61004468818981.

It can be written as a sum of positive squares in 2 ways, for example, as 6528045440016 + 12453841000000 = 2555004^2 + 3529000^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18981886440016.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6115296915 + ... + 6115300018.

Almost surely, 2^{18981886440016} is an apocalyptic number.

18981886440016 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

18981886440016 is a deficient number, since it is larger than the sum of its proper divisors (18174667045476).

18981886440016 is a wasteful number, since it uses less digits than its factorization.

18981886440016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12230597038 (or 12230597032 counting only the distinct ones).

The product of its (nonzero) digits is 21233664, while the sum is 64.

The spelling of 18981886440016 in words is "eighteen trillion, nine hundred eighty-one billion, eight hundred eighty-six million, four hundred forty thousand, sixteen".