128911197 has 4 divisors (see below), whose sum is σ = 171881600. Its totient is φ = 85940796.

The previous prime is 128911183. The next prime is 128911207. The reversal of 128911197 is 791119821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 128911197 - 2¹² = 128907101 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 (128911127) 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, 21485197 + ... + 21485202.

It is an arithmetic number, because the mean of its divisors is an integer number (42970400).

Almost surely, 2^128911197 is an apocalyptic number.

It is an amenable number.

128911197 is a deficient number, since it is larger than the sum of its proper divisors (42970403).

128911197 is an equidigital number, since it uses as much as digits as its factorization.

128911197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42970402.

The product of its digits is 9072, while the sum is 39.

The square root of 128911197 is about 11353.9066844853. The cubic root of 128911197 is about 505.1614645604.

The spelling of 128911197 in words is "one hundred twenty-eight million, nine hundred eleven thousand, one hundred ninety-seven".