128122879 has 4 divisors (see below), whose sum is σ = 128146320. Its totient is φ = 128099440.

The previous prime is 128122861. The next prime is 128122913. The reversal of 128122879 is 978221821.

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

It is a cyclic number.

It is not a de Polignac number, because 128122879 - 2⁷ = 128122751 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 (128122849) 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, 1302 + ... + 16060.

It is an arithmetic number, because the mean of its divisors is an integer number (32036580).

Almost surely, 2^128122879 is an apocalyptic number.

128122879 is a deficient number, since it is larger than the sum of its proper divisors (23441).

128122879 is an equidigital number, since it uses as much as digits as its factorization.

128122879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23440.

The product of its digits is 32256, while the sum is 40.

The square root of 128122879 is about 11319.1377321773. The cubic root of 128122879 is about 504.1296369619.

The spelling of 128122879 in words is "one hundred twenty-eight million, one hundred twenty-two thousand, eight hundred seventy-nine".