81170128 has 120 divisors (see below), whose sum is σ = 190487808. Its totient is φ = 33225984.

The previous prime is 81170057. The next prime is 81170129. The reversal of 81170128 is 82107118.

It is a junction number, because it is equal to n+sod(n) for n = 81170096 and 81170105.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81170129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1727001 + ... + 1727047.

Almost surely, 2^81170128 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 81170128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95243904).

81170128 is an abundant number, since it is smaller than the sum of its proper divisors (109317680).

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

81170128 is a wasteful number, since it uses less digits than its factorization.

81170128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129 (or 104 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 28.

The square root of 81170128 is about 9009.4465978771. The cubic root of 81170128 is about 432.9775815242.

The spelling of 81170128 in words is "eighty-one million, one hundred seventy thousand, one hundred twenty-eight".