12115661 has 2 divisors, whose sum is σ = 12115662. Its totient is φ = 12115660.

The previous prime is 12115651. The next prime is 12115669. The reversal of 12115661 is 16651121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11095561 + 1020100 = 3331^2 + 1010^2 .

It is an emirp because it is prime and its reverse (16651121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12115661 - 2¹⁰ = 12114637 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12115669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6057830 + 6057831.

It is an arithmetic number, because the mean of its divisors is an integer number (6057831).

Almost surely, 2^12115661 is an apocalyptic number.

It is an amenable number.

12115661 is a deficient number, since it is larger than the sum of its proper divisors (1).

12115661 is an equidigital number, since it uses as much as digits as its factorization.

12115661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 360, while the sum is 23.

The square root of 12115661 is about 3480.7558087289. The cubic root of 12115661 is about 229.6760467641.

Adding to 12115661 its reverse (16651121), we get a palindrome (28766782).

It can be divided in two parts, 121 and 15661, that multiplied together give a palindrome (1894981).

The spelling of 12115661 in words is "twelve million, one hundred fifteen thousand, six hundred sixty-one".