81128322 has 54 divisors (see below), whose sum is σ = 194216841. Its totient is φ = 24456960.

The previous prime is 81128321. The next prime is 81128329. The reversal of 81128322 is 22382118.

It can be written as a sum of positive squares in 2 ways, for example, as 75325041 + 5803281 = 8679^2 + 2409^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=6369.

It is not an unprimeable number, because it can be changed into a prime (81128321) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 420258 + ... + 420450.

Almost surely, 2^81128322 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81128322

81128322 is an abundant number, since it is smaller than the sum of its proper divisors (113088519).

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

81128322 is a wasteful number, since it uses less digits than its factorization.

81128322 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 416 (or 209 counting only the distinct ones).

The product of its digits is 1536, while the sum is 27.

The square root of 81128322 is about 9007.1261787542. The cubic root of 81128322 is about 432.9032349236.

The spelling of 81128322 in words is "eighty-one million, one hundred twenty-eight thousand, three hundred twenty-two".