12681209 has 2 divisors, whose sum is σ = 12681210. Its totient is φ = 12681208.

The previous prime is 12681203. The next prime is 12681217. The reversal of 12681209 is 90218621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6786025 + 5895184 = 2605^2 + 2428^2 .

It is an emirp because it is prime and its reverse (90218621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12681209 - 2²⁰ = 11632633 is a prime.

It is not a weakly prime, because it can be changed into another prime (12681203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6340604 + 6340605.

It is an arithmetic number, because the mean of its divisors is an integer number (6340605).

Almost surely, 2^12681209 is an apocalyptic number.

It is an amenable number.

12681209 is a deficient number, since it is larger than the sum of its proper divisors (1).

12681209 is an equidigital number, since it uses as much as digits as its factorization.

12681209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 12681209 is about 3561.0685194194. The cubic root of 12681209 is about 233.1955292881.

The spelling of 12681209 in words is "twelve million, six hundred eighty-one thousand, two hundred nine".