81128443 has 8 divisors (see below), whose sum is σ = 89236656. Its totient is φ = 73751920.

The previous prime is 81128419. The next prime is 81128473. The reversal of 81128443 is 34482118.

It is a de Polignac number, because none of the positive numbers 2^k-81128443 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81128413) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29146 + ... + 31807.

It is an arithmetic number, because the mean of its divisors is an integer number (11154582).

Almost surely, 2^81128443 is an apocalyptic number.

81128443 is a deficient number, since it is larger than the sum of its proper divisors (8108213).

81128443 is an equidigital number, since it uses as much as digits as its factorization.

81128443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60986 (or 60964 counting only the distinct ones).

The product of its digits is 6144, while the sum is 31.

The square root of 81128443 is about 9007.1328956555. The cubic root of 81128443 is about 432.9034501434.

The spelling of 81128443 in words is "eighty-one million, one hundred twenty-eight thousand, four hundred forty-three".