1268591309 has 2 divisors, whose sum is σ = 1268591310. Its totient is φ = 1268591308.

The previous prime is 1268591281. The next prime is 1268591329. The reversal of 1268591309 is 9031958621.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1102439209 + 166152100 = 33203^2 + 12890^2 .

It is a cyclic number.

It is not a de Polignac number, because 1268591309 - 2²⁴ = 1251814093 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1268591309.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1268591329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 634295654 + 634295655.

It is an arithmetic number, because the mean of its divisors is an integer number (634295655).

Almost surely, 2^1268591309 is an apocalyptic number.

It is an amenable number.

1268591309 is a deficient number, since it is larger than the sum of its proper divisors (1).

1268591309 is an equidigital number, since it uses as much as digits as its factorization.

1268591309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 116640, while the sum is 44.

The square root of 1268591309 is about 35617.2894673359. The cubic root of 1268591309 is about 1082.5315866026.

The spelling of 1268591309 in words is "one billion, two hundred sixty-eight million, five hundred ninety-one thousand, three hundred nine".