128911285 has 4 divisors (see below), whose sum is σ = 154693548. Its totient is φ = 103129024.

The previous prime is 128911273. The next prime is 128911301. The reversal of 128911285 is 582119821.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 58384881 + 70526404 = 7641^2 + 8398^2 .

It is a cyclic number.

It is not a de Polignac number, because 128911285 - 2⁵ = 128911253 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 12891124 + ... + 12891133.

It is an arithmetic number, because the mean of its divisors is an integer number (38673387).

Almost surely, 2^128911285 is an apocalyptic number.

It is an amenable number.

128911285 is a deficient number, since it is larger than the sum of its proper divisors (25782263).

128911285 is an equidigital number, since it uses as much as digits as its factorization.

128911285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25782262.

The product of its digits is 11520, while the sum is 37.

The square root of 128911285 is about 11353.9105598027. The cubic root of 128911285 is about 505.1615795082.

The spelling of 128911285 in words is "one hundred twenty-eight million, nine hundred eleven thousand, two hundred eighty-five".