81168168 has 32 divisors (see below), whose sum is σ = 209468160. Its totient is φ = 26183040.

The previous prime is 81168161. The next prime is 81168169. The reversal of 81168168 is 86186118.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

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 (81168161) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53805 + ... + 55292.

It is an arithmetic number, because the mean of its divisors is an integer number (6545880).

Almost surely, 2^81168168 is an apocalyptic number.

It is an amenable number.

81168168 is an abundant number, since it is smaller than the sum of its proper divisors (128299992).

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

81168168 is a wasteful number, since it uses less digits than its factorization.

81168168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109137 (or 109133 counting only the distinct ones).

The product of its digits is 18432, while the sum is 39.

The square root of 81168168 is about 9009.3378225039. The cubic root of 81168168 is about 432.9740964864.

The spelling of 81168168 in words is "eighty-one million, one hundred sixty-eight thousand, one hundred sixty-eight".