12866309 has 2 divisors, whose sum is σ = 12866310. Its totient is φ = 12866308.

The previous prime is 12866281. The next prime is 12866311. The reversal of 12866309 is 90366821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7562500 + 5303809 = 2750^2 + 2303^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12866309 is a prime.

Together with 12866311, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12866339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6433154 + 6433155.

It is an arithmetic number, because the mean of its divisors is an integer number (6433155).

Almost surely, 2^12866309 is an apocalyptic number.

It is an amenable number.

12866309 is a deficient number, since it is larger than the sum of its proper divisors (1).

12866309 is an equidigital number, since it uses as much as digits as its factorization.

12866309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 12866309 is about 3586.9637578320. The cubic root of 12866309 is about 234.3246583197.

The spelling of 12866309 in words is "twelve million, eight hundred sixty-six thousand, three hundred nine".