81941328 has 200 divisors, whose sum is σ = 277859200. Its totient is φ = 23115456.

The previous prime is 81941303. The next prime is 81941369. The reversal of 81941328 is 82314918.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 81941292 and 81941301.

It is a congruent number.

It is an unprimeable number.

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 39 ways as a sum of consecutive naturals, for example, 1037193 + ... + 1037271.

It is an arithmetic number, because the mean of its divisors is an integer number (1389296).

Almost surely, 2^81941328 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 81941328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138929600).

81941328 is an abundant number, since it is smaller than the sum of its proper divisors (195917872).

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

81941328 is an equidigital number, since it uses as much as digits as its factorization.

81941328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124 (or 91 counting only the distinct ones).

The product of its digits is 13824, while the sum is 36.

The square root of 81941328 is about 9052.1449391843. The cubic root of 81941328 is about 434.3445062043.

The spelling of 81941328 in words is "eighty-one million, nine hundred forty-one thousand, three hundred twenty-eight".