128755217 has 2 divisors, whose sum is σ = 128755218. Its totient is φ = 128755216.

The previous prime is 128755199. The next prime is 128755223. The reversal of 128755217 is 712557821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64899136 + 63856081 = 8056^2 + 7991^2 .

It is a cyclic number.

It is not a de Polignac number, because 128755217 - 2¹⁰ = 128754193 is a prime.

It is not a weakly prime, because it can be changed into another prime (128755117) 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 as a sum of consecutive naturals, namely, 64377608 + 64377609.

It is an arithmetic number, because the mean of its divisors is an integer number (64377609).

Almost surely, 2^128755217 is an apocalyptic number.

It is an amenable number.

128755217 is a deficient number, since it is larger than the sum of its proper divisors (1).

128755217 is an equidigital number, since it uses as much as digits as its factorization.

128755217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 39200, while the sum is 38.

The square root of 128755217 is about 11347.0356040686. The cubic root of 128755217 is about 504.9576372006.

The spelling of 128755217 in words is "one hundred twenty-eight million, seven hundred fifty-five thousand, two hundred seventeen".