81068928 has 128 divisors (see below), whose sum is σ = 229720320. Its totient is φ = 25276416.

The previous prime is 81068927. The next prime is 81068941. The reversal of 81068928 is 82986018.

It is a tau number, because it is divible by the number of its divisors (128).

It is a self number, because there is not a number n which added to its sum of digits gives 81068928.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81068927) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 591676 + ... + 591812.

It is an arithmetic number, because the mean of its divisors is an integer number (1794690).

Almost surely, 2^81068928 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 81068928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114860160).

81068928 is an abundant number, since it is smaller than the sum of its proper divisors (148651392).

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

81068928 is a wasteful number, since it uses less digits than its factorization.

81068928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244 (or 232 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 42.

The square root of 81068928 is about 9003.8285190246. The cubic root of 81068928 is about 432.7975663925.

The spelling of 81068928 in words is "eighty-one million, sixty-eight thousand, nine hundred twenty-eight".