128812709 has 2 divisors, whose sum is σ = 128812710. Its totient is φ = 128812708.

The previous prime is 128812703. The next prime is 128812721. The reversal of 128812709 is 907218821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 128709025 + 103684 = 11345^2 + 322^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128812709 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128812703) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64406354 + 64406355.

It is an arithmetic number, because the mean of its divisors is an integer number (64406355).

Almost surely, 2^128812709 is an apocalyptic number.

It is an amenable number.

128812709 is a deficient number, since it is larger than the sum of its proper divisors (1).

128812709 is an equidigital number, since it uses as much as digits as its factorization.

128812709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16128, while the sum is 38.

The square root of 128812709 is about 11349.5686702183. The cubic root of 128812709 is about 505.0327841998.

The spelling of 128812709 in words is "one hundred twenty-eight million, eight hundred twelve thousand, seven hundred nine".