128039278805 has 16 divisors (see below), whose sum is σ = 160583940720. Its totient is φ = 97879713792.

The previous prime is 128039278789. The next prime is 128039278817. The reversal of 128039278805 is 508872930821.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 6629542084 + 121409736721 = 81422^2 + 348439^2 .

It is a cyclic number.

It is not a de Polignac number, because 128039278805 - 2⁴ = 128039278789 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4537634 + ... + 4565763.

It is an arithmetic number, because the mean of its divisors is an integer number (10036496295).

Almost surely, 2^128039278805 is an apocalyptic number.

It is an amenable number.

128039278805 is a deficient number, since it is larger than the sum of its proper divisors (32544661915).

128039278805 is an equidigital number, since it uses as much as digits as its factorization.

128039278805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9103528.

The product of its (nonzero) digits is 1935360, while the sum is 53.

The spelling of 128039278805 in words is "one hundred twenty-eight billion, thirty-nine million, two hundred seventy-eight thousand, eight hundred five".