81161841168 has 60 divisors (see below), whose sum is σ = 227773278720. Its totient is φ = 26978570688.

The previous prime is 81161841157. The next prime is 81161841221. The reversal of 81161841168 is 86114816118.

81161841168 is a `hidden beast` number, since 8 + 11 + 618 + 4 + 1 + 16 + 8 = 666.

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 11 ways as a sum of consecutive naturals, for example, 733296 + ... + 836687.

It is an arithmetic number, because the mean of its divisors is an integer number (3796221312).

Almost surely, 2^81161841168 is an apocalyptic number.

It is an amenable number.

81161841168 is an abundant number, since it is smaller than the sum of its proper divisors (146611437552).

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

81161841168 is a wasteful number, since it uses less digits than its factorization.

81161841168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1570356 (or 1570347 counting only the distinct ones).

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

The spelling of 81161841168 in words is "eighty-one billion, one hundred sixty-one million, eight hundred forty-one thousand, one hundred sixty-eight".