81128433 has 16 divisors (see below), whose sum is σ = 110186496. Its totient is φ = 53086800.

The previous prime is 81128419. The next prime is 81128473. The reversal of 81128433 is 33482118.

It is not a de Polignac number, because 81128433 - 2¹⁶ = 81062897 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 81128433.

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 (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40608 + ... + 42558.

It is an arithmetic number, because the mean of its divisors is an integer number (6886656).

Almost surely, 2^81128433 is an apocalyptic number.

81128433 is a gapful number since it is divisible by the number (83) formed by its first and last digit.

It is an amenable number.

81128433 is a deficient number, since it is larger than the sum of its proper divisors (29058063).

81128433 is a wasteful number, since it uses less digits than its factorization.

81128433 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2204.

The product of its digits is 4608, while the sum is 30.

The square root of 81128433 is about 9007.1323405399. The cubic root of 81128433 is about 432.9034323566.

The spelling of 81128433 in words is "eighty-one million, one hundred twenty-eight thousand, four hundred thirty-three".