81098928 has 80 divisors (see below), whose sum is σ = 234092160. Its totient is φ = 26881344.

The previous prime is 81098911. The next prime is 81098987. The reversal of 81098928 is 82989018.

It is a super-2 number, since 2×81098928² = 13154072245498368, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 97651 + ... + 98477.

It is an arithmetic number, because the mean of its divisors is an integer number (2926152).

Almost surely, 2^81098928 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 81098928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117046080).

81098928 is an abundant number, since it is smaller than the sum of its proper divisors (152993232).

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

81098928 is a wasteful number, since it uses less digits than its factorization.

81098928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1071 (or 1059 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 45.

The square root of 81098928 is about 9005.4943229120. The cubic root of 81098928 is about 432.8509461771.

The spelling of 81098928 in words is "eighty-one million, ninety-eight thousand, nine hundred twenty-eight".