12866389 has 2 divisors, whose sum is σ = 12866390. Its totient is φ = 12866388.

The previous prime is 12866387. The next prime is 12866393. The reversal of 12866389 is 98366821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12659364 + 207025 = 3558^2 + 455^2 .

It is a cyclic number.

It is not a de Polignac number, because 12866389 - 2¹ = 12866387 is a prime.

Together with 12866387, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12866387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6433194 + 6433195.

It is an arithmetic number, because the mean of its divisors is an integer number (6433195).

Almost surely, 2^12866389 is an apocalyptic number.

It is an amenable number.

12866389 is a deficient number, since it is larger than the sum of its proper divisors (1).

12866389 is an equidigital number, since it uses as much as digits as its factorization.

12866389 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 124416, while the sum is 43.

The square root of 12866389 is about 3586.9749093073. The cubic root of 12866389 is about 234.3251439791.

The spelling of 12866389 in words is "twelve million, eight hundred sixty-six thousand, three hundred eighty-nine".