81168672 has 72 divisors (see below), whose sum is σ = 230764464. Its totient is φ = 24969984.

The previous prime is 81168653. The next prime is 81168673. The reversal of 81168672 is 27686118.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 81168672.

It is not an unprimeable number, because it can be changed into a prime (81168673) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13723 + ... + 18725.

It is an arithmetic number, because the mean of its divisors is an integer number (3205062).

Almost surely, 2^81168672 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 81168672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115382232).

81168672 is an abundant number, since it is smaller than the sum of its proper divisors (149595792).

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

81168672 is a wasteful number, since it uses less digits than its factorization.

81168672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5042 (or 5021 counting only the distinct ones).

The product of its digits is 32256, while the sum is 39.

The square root of 81168672 is about 9009.3657934396. The cubic root of 81168672 is about 432.9749926443.

The spelling of 81168672 in words is "eighty-one million, one hundred sixty-eight thousand, six hundred seventy-two".