115128891 has 8 divisors (see below), whose sum is σ = 170561360. Its totient is φ = 76752576.

The previous prime is 115128889. The next prime is 115128901. The reversal of 115128891 is 198821511.

It is not a de Polignac number, because 115128891 - 2¹ = 115128889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (115128821) 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 7 ways as a sum of consecutive naturals, for example, 2131990 + ... + 2132043.

It is an arithmetic number, because the mean of its divisors is an integer number (21320170).

Almost surely, 2^115128891 is an apocalyptic number.

115128891 is a deficient number, since it is larger than the sum of its proper divisors (55432469).

115128891 is an equidigital number, since it uses as much as digits as its factorization.

115128891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4264042 (or 4264036 counting only the distinct ones).

The product of its digits is 5760, while the sum is 36.

The square root of 115128891 is about 10729.8131856990. The cubic root of 115128891 is about 486.4760234604.

The spelling of 115128891 in words is "one hundred fifteen million, one hundred twenty-eight thousand, eight hundred ninety-one".