18681819863616 has 1792 divisors, whose sum is σ = 70868128235520. Its totient is φ = 4695400120320.

The previous prime is 18681819863599. The next prime is 18681819863617. The reversal of 18681819863616 is 61636891818681.

18681819863616 is a `hidden beast` number, since 1 + 8 + 6 + 8 + 181 + 9 + 86 + 361 + 6 = 666.

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

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

It is not an unprimeable number, because it can be changed into a prime (18681819863617) by changing a digit.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 96796994016 + ... + 96796994208.

It is an arithmetic number, because the mean of its divisors is an integer number (39546946560).

Almost surely, 2^{18681819863616} is an apocalyptic number.

18681819863616 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 18681819863616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35434064117760).

18681819863616 is an abundant number, since it is smaller than the sum of its proper divisors (52186308371904).

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

18681819863616 is a wasteful number, since it uses less digits than its factorization.

18681819863616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 529 (or 513 counting only the distinct ones).

The product of its digits is 143327232, while the sum is 72.

The spelling of 18681819863616 in words is "eighteen trillion, six hundred eighty-one billion, eight hundred nineteen million, eight hundred sixty-three thousand, six hundred sixteen".