128777019817 has 2 divisors, whose sum is σ = 128777019818. Its totient is φ = 128777019816.

The previous prime is 128777019799. The next prime is 128777019883. The reversal of 128777019817 is 718910777821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 127394741776 + 1382278041 = 356924^2 + 37179^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128777019817 is a prime.

It is not a weakly prime, because it can be changed into another prime (128777019517) 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, 64388509908 + 64388509909.

It is an arithmetic number, because the mean of its divisors is an integer number (64388509909).

Almost surely, 2^128777019817 is an apocalyptic number.

It is an amenable number.

128777019817 is a deficient number, since it is larger than the sum of its proper divisors (1).

128777019817 is an equidigital number, since it uses as much as digits as its factorization.

128777019817 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2765952, while the sum is 58.

The spelling of 128777019817 in words is "one hundred twenty-eight billion, seven hundred seventy-seven million, nineteen thousand, eight hundred seventeen".