128309394079 has 4 divisors (see below), whose sum is σ = 128310245280. Its totient is φ = 128308542880.

The previous prime is 128309394053. The next prime is 128309394091. The reversal of 128309394079 is 970493903821.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 970493903821 = 13 ⋅74653377217.

It is a cyclic number.

It is not a de Polignac number, because 128309394079 - 2⁵ = 128309394047 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 (128309394979) 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, 131959 + ... + 523480.

It is an arithmetic number, because the mean of its divisors is an integer number (32077561320).

Almost surely, 2^128309394079 is an apocalyptic number.

128309394079 is a deficient number, since it is larger than the sum of its proper divisors (851201).

128309394079 is an equidigital number, since it uses as much as digits as its factorization.

128309394079 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 851200.

The product of its (nonzero) digits is 2939328, while the sum is 55.

The spelling of 128309394079 in words is "one hundred twenty-eight billion, three hundred nine million, three hundred ninety-four thousand, seventy-nine".