12409561 has 2 divisors, whose sum is σ = 12409562. Its totient is φ = 12409560.

The previous prime is 12409549. The next prime is 12409571. The reversal of 12409561 is 16590421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9960336 + 2449225 = 3156^2 + 1565^2 .

It is an emirp because it is prime and its reverse (16590421) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12409561 - 2⁷ = 12409433 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (12409531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6204780 + 6204781.

It is an arithmetic number, because the mean of its divisors is an integer number (6204781).

Almost surely, 2^12409561 is an apocalyptic number.

It is an amenable number.

12409561 is a deficient number, since it is larger than the sum of its proper divisors (1).

12409561 is an equidigital number, since it uses as much as digits as its factorization.

12409561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 12409561 is about 3522.7206815188. The cubic root of 12409561 is about 231.5183788415.

Adding to 12409561 its reverse (16590421), we get a palindrome (28999982).

It can be divided in two parts, 1240 and 9561, that added together give a palindrome (10801).

The spelling of 12409561 in words is "twelve million, four hundred nine thousand, five hundred sixty-one".