18031981800408 has 128 divisors (see below), whose sum is σ = 45702524851200. Its totient is φ = 5927913230976.

The previous prime is 18031981800397. The next prime is 18031981800439. The reversal of 18031981800408 is 80400818913081.

It is a happy number.

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, 4155789903 + ... + 4155794241.

It is an arithmetic number, because the mean of its divisors is an integer number (357050975400).

Almost surely, 2^{18031981800408} is an apocalyptic number.

It is an amenable number.

18031981800408 is an abundant number, since it is smaller than the sum of its proper divisors (27670543050792).

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

18031981800408 is a wasteful number, since it uses less digits than its factorization.

18031981800408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7581 (or 7577 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 51.

The spelling of 18031981800408 in words is "eighteen trillion, thirty-one billion, nine hundred eighty-one million, eight hundred thousand, four hundred eight".