128190681161 has 4 divisors (see below), whose sum is σ = 128336187924. Its totient is φ = 128045174400.

The previous prime is 128190681097. The next prime is 128190681173. The reversal of 128190681161 is 161186091821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 161186091821 = 17 ⋅9481534813.

It can be written as a sum of positive squares in 2 ways, for example, as 9988803136 + 118201878025 = 99944^2 + 343805^2 .

It is a cyclic number.

It is not a de Polignac number, because 128190681161 - 2⁶ = 128190681097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128190683161) 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, 72752060 + ... + 72753821.

It is an arithmetic number, because the mean of its divisors is an integer number (32084046981).

Almost surely, 2^128190681161 is an apocalyptic number.

It is an amenable number.

128190681161 is a deficient number, since it is larger than the sum of its proper divisors (145506763).

128190681161 is an equidigital number, since it uses as much as digits as its factorization.

128190681161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145506762.

The product of its (nonzero) digits is 41472, while the sum is 44.

The spelling of 128190681161 in words is "one hundred twenty-eight billion, one hundred ninety million, six hundred eighty-one thousand, one hundred sixty-one".