128319717209 has 2 divisors, whose sum is σ = 128319717210. Its totient is φ = 128319717208.

The previous prime is 128319717107. The next prime is 128319717221. The reversal of 128319717209 is 902717913821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 124580761600 + 3738955609 = 352960^2 + 61147^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128319717209 is a prime.

It is not a weakly prime, because it can be changed into another prime (128319714209) by changing a digit.

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 as a sum of consecutive naturals, namely, 64159858604 + 64159858605.

It is an arithmetic number, because the mean of its divisors is an integer number (64159858605).

Almost surely, 2^128319717209 is an apocalyptic number.

It is an amenable number.

128319717209 is a deficient number, since it is larger than the sum of its proper divisors (1).

128319717209 is an equidigital number, since it uses as much as digits as its factorization.

128319717209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 381024, while the sum is 50.

The spelling of 128319717209 in words is "one hundred twenty-eight billion, three hundred nineteen million, seven hundred seventeen thousand, two hundred nine".