13661309 has 2 divisors, whose sum is σ = 13661310. Its totient is φ = 13661308.

The previous prime is 13661303. The next prime is 13661311. The reversal of 13661309 is 90316631.

13661309 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6916900 + 6744409 = 2630^2 + 2597^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13661309 is a prime.

Together with 13661311, 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 (13661303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6830654 + 6830655.

It is an arithmetic number, because the mean of its divisors is an integer number (6830655).

Almost surely, 2^13661309 is an apocalyptic number.

It is an amenable number.

13661309 is a deficient number, since it is larger than the sum of its proper divisors (1).

13661309 is an equidigital number, since it uses as much as digits as its factorization.

13661309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2916, while the sum is 29.

The square root of 13661309 is about 3696.1208043028. The cubic root of 13661309 is about 239.0547834011.

The spelling of 13661309 in words is "thirteen million, six hundred sixty-one thousand, three hundred nine".