128170309 has 2 divisors, whose sum is σ = 128170310. Its totient is φ = 128170308.

The previous prime is 128170279. The next prime is 128170369. The reversal of 128170309 is 903071821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 114554209 + 13616100 = 10703^2 + 3690^2 .

It is a cyclic number.

It is not a de Polignac number, because 128170309 - 2⁵ = 128170277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128170369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64085154 + 64085155.

It is an arithmetic number, because the mean of its divisors is an integer number (64085155).

Almost surely, 2^128170309 is an apocalyptic number.

It is an amenable number.

128170309 is a deficient number, since it is larger than the sum of its proper divisors (1).

128170309 is an equidigital number, since it uses as much as digits as its factorization.

128170309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 128170309 is about 11321.2326625682. The cubic root of 128170309 is about 504.1918374550.

The spelling of 128170309 in words is "one hundred twenty-eight million, one hundred seventy thousand, three hundred nine".