18989405405856 has 240 divisors, whose sum is σ = 56122897057920. Its totient is φ = 6298606863360.

The previous prime is 18989405405807. The next prime is 18989405405879. The reversal of 18989405405856 is 65850450498981.

18989405405856 is a `hidden beast` number, since 1 + 8 + 9 + 89 + 405 + 40 + 58 + 56 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 883998636 + ... + 884020116.

It is an arithmetic number, because the mean of its divisors is an integer number (233845404408).

Almost surely, 2^{18989405405856} is an apocalyptic number.

18989405405856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18989405405856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28061448528960).

18989405405856 is an abundant number, since it is smaller than the sum of its proper divisors (37133491652064).

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

18989405405856 is a wasteful number, since it uses less digits than its factorization.

18989405405856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23169 (or 23152 counting only the distinct ones).

The product of its (nonzero) digits is 497664000, while the sum is 72.

The spelling of 18989405405856 in words is "eighteen trillion, nine hundred eighty-nine billion, four hundred five million, four hundred five thousand, eight hundred fifty-six".