128788189 has 4 divisors (see below), whose sum is σ = 128824380. Its totient is φ = 128752000.

The previous prime is 128788181. The next prime is 128788193. The reversal of 128788189 is 981887821.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 981887821 = 1559 ⋅629819.

It can be written as a sum of positive squares in 2 ways, for example, as 18852964 + 109935225 = 4342^2 + 10485^2 .

It is a cyclic number.

It is not a de Polignac number, because 128788189 - 2³ = 128788181 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128788181) 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 3 ways as a sum of consecutive naturals, for example, 12094 + ... + 20095.

It is an arithmetic number, because the mean of its divisors is an integer number (32206095).

Almost surely, 2^128788189 is an apocalyptic number.

It is an amenable number.

128788189 is a deficient number, since it is larger than the sum of its proper divisors (36191).

128788189 is an equidigital number, since it uses as much as digits as its factorization.

128788189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36190.

The product of its digits is 516096, while the sum is 52.

The square root of 128788189 is about 11348.4884015449. The cubic root of 128788189 is about 505.0007371816. Note that the first 3 decimals are identical.

The spelling of 128788189 in words is "one hundred twenty-eight million, seven hundred eighty-eight thousand, one hundred eighty-nine".