128122999 has 4 divisors (see below), whose sum is σ = 135659664. Its totient is φ = 120586336.

The previous prime is 128122963. The next prime is 128123011. The reversal of 128122999 is 999221821.

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 128122999 - 2¹⁵ = 128090231 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 (128122919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3768307 + ... + 3768340.

It is an arithmetic number, because the mean of its divisors is an integer number (33914916).

Almost surely, 2^128122999 is an apocalyptic number.

128122999 is a deficient number, since it is larger than the sum of its proper divisors (7536665).

128122999 is an equidigital number, since it uses as much as digits as its factorization.

128122999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7536664.

The product of its digits is 46656, while the sum is 43.

The square root of 128122999 is about 11319.1430329332. The cubic root of 128122999 is about 504.1297943513.

The spelling of 128122999 in words is "one hundred twenty-eight million, one hundred twenty-two thousand, nine hundred ninety-nine".