81995928 has 64 divisors (see below), whose sum is σ = 235269120. Its totient is φ = 23328000.

The previous prime is 81995923. The next prime is 81995939. The reversal of 81995928 is 82959918.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81995923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 44628 + ... + 46428.

It is an arithmetic number, because the mean of its divisors is an integer number (3676080).

Almost surely, 2^81995928 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 81995928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117634560).

81995928 is an abundant number, since it is smaller than the sum of its proper divisors (153273192).

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

81995928 is a wasteful number, since it uses less digits than its factorization.

81995928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2088 (or 2084 counting only the distinct ones).

The product of its digits is 466560, while the sum is 51.

The square root of 81995928 is about 9055.1602967590. The cubic root of 81995928 is about 434.4409571047.

The spelling of 81995928 in words is "eighty-one million, nine hundred ninety-five thousand, nine hundred twenty-eight".