12906115661 has 2 divisors, whose sum is σ = 12906115662. Its totient is φ = 12906115660.

The previous prime is 12906115637. The next prime is 12906115711. The reversal of 12906115661 is 16651160921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8575686025 + 4330429636 = 92605^2 + 65806^2 .

It is a cyclic number.

It is not a de Polignac number, because 12906115661 - 2¹⁸ = 12905853517 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12906117661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6453057830 + 6453057831.

It is an arithmetic number, because the mean of its divisors is an integer number (6453057831).

Almost surely, 2^12906115661 is an apocalyptic number.

It is an amenable number.

12906115661 is a deficient number, since it is larger than the sum of its proper divisors (1).

12906115661 is an equidigital number, since it uses as much as digits as its factorization.

12906115661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19440, while the sum is 38.

The spelling of 12906115661 in words is "twelve billion, nine hundred six million, one hundred fifteen thousand, six hundred sixty-one".