81113081868 has 576 divisors, whose sum is σ = 277196308480. Its totient is φ = 19399564800.

The previous prime is 81113081857. The next prime is 81113081953. The reversal of 81113081868 is 86818031118.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 245054463 + ... + 245054793.

Almost surely, 2^81113081868 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81113081868, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138598154240).

81113081868 is an abundant number, since it is smaller than the sum of its proper divisors (196083226612).

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

81113081868 is a wasteful number, since it uses less digits than its factorization.

81113081868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 538 (or 533 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 45.

The spelling of 81113081868 in words is "eighty-one billion, one hundred thirteen million, eighty-one thousand, eight hundred sixty-eight".