18819891696816 has 400 divisors, whose sum is σ = 64115957030400. Its totient is φ = 5326845068160.

The previous prime is 18819891696751. The next prime is 18819891696857. The reversal of 18819891696816 is 61869619891881.

18819891696816 is a `hidden beast` number, since 188 + 198 + 91 + 6 + 96 + 81 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 47366661 + ... + 47762331.

It is an arithmetic number, because the mean of its divisors is an integer number (160289892576).

Almost surely, 2^{18819891696816} is an apocalyptic number.

18819891696816 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 18819891696816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32057978515200).

18819891696816 is an abundant number, since it is smaller than the sum of its proper divisors (45296065333584).

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

18819891696816 is a wasteful number, since it uses less digits than its factorization.

18819891696816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 395819 (or 395790 counting only the distinct ones).

The product of its digits is 644972544, while the sum is 81.

The spelling of 18819891696816 in words is "eighteen trillion, eight hundred nineteen billion, eight hundred ninety-one million, six hundred ninety-six thousand, eight hundred sixteen".