128706881 has 4 divisors (see below), whose sum is σ = 136277892. Its totient is φ = 121135872.

The previous prime is 128706871. The next prime is 128706899. The reversal of 128706881 is 188607821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 188607821 = 89 ⋅2119189.

It can be written as a sum of positive squares in 2 ways, for example, as 71250481 + 57456400 = 8441^2 + 7580^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128706881 is a prime.

It is a super-2 number, since 2×128706881² = 33130922433496322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (128706841) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3785480 + ... + 3785513.

It is an arithmetic number, because the mean of its divisors is an integer number (34069473).

Almost surely, 2^128706881 is an apocalyptic number.

It is an amenable number.

128706881 is a deficient number, since it is larger than the sum of its proper divisors (7571011).

128706881 is an equidigital number, since it uses as much as digits as its factorization.

128706881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7571010.

The product of its (nonzero) digits is 43008, while the sum is 41.

The square root of 128706881 is about 11344.9055086413. The cubic root of 128706881 is about 504.8944405710.

The spelling of 128706881 in words is "one hundred twenty-eight million, seven hundred six thousand, eight hundred eighty-one".