81086928 has 80 divisors (see below), whose sum is σ = 227068800. Its totient is φ = 24786432.

The previous prime is 81086909. The next prime is 81086947. The reversal of 81086928 is 82968018.

It is an interprime number because it is at equal distance from previous prime (81086909) and next prime (81086947).

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 81086928.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 123850 + ... + 124502.

It is an arithmetic number, because the mean of its divisors is an integer number (2838360).

Almost surely, 2^81086928 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 81086928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113534400).

81086928 is an abundant number, since it is smaller than the sum of its proper divisors (145981872).

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

81086928 is a wasteful number, since it uses less digits than its factorization.

81086928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 876 (or 870 counting only the distinct ones).

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

The square root of 81086928 is about 9004.8280383359. The cubic root of 81086928 is about 432.8295958432.

The spelling of 81086928 in words is "eighty-one million, eighty-six thousand, nine hundred twenty-eight".