81443328 has 80 divisors (see below), whose sum is σ = 229806720. Its totient is φ = 25542656.

The previous prime is 81443321. The next prime is 81443347. The reversal of 81443328 is 82334418.

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

It is not an unprimeable number, because it can be changed into a prime (81443321) 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 7 ways as a sum of consecutive naturals, for example, 24553 + ... + 27671.

It is an arithmetic number, because the mean of its divisors is an integer number (2872584).

Almost surely, 2^81443328 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 81443328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114903360).

81443328 is an abundant number, since it is smaller than the sum of its proper divisors (148363392).

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

81443328 is a wasteful number, since it uses less digits than its factorization.

81443328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3157 (or 3141 counting only the distinct ones).

The product of its digits is 18432, while the sum is 33.

The square root of 81443328 is about 9024.5957250173. The cubic root of 81443328 is about 433.4628052308.

The spelling of 81443328 in words is "eighty-one million, four hundred forty-three thousand, three hundred twenty-eight".