9912123363209 has 2 divisors, whose sum is σ = 9912123363210. Its totient is φ = 9912123363208.

The previous prime is 9912123363203. The next prime is 9912123363239. The reversal of 9912123363209 is 9023633212199.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8826526076809 + 1085597286400 = 2970947^2 + 1041920^2 .

It is a cyclic number.

It is not a de Polignac number, because 9912123363209 - 2¹² = 9912123359113 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (9912123363203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4956061681604 + 4956061681605.

It is an arithmetic number, because the mean of its divisors is an integer number (4956061681605).

Almost surely, 2^{9912123363209} is an apocalyptic number.

It is an amenable number.

9912123363209 is a deficient number, since it is larger than the sum of its proper divisors (1).

9912123363209 is an equidigital number, since it uses as much as digits as its factorization.

9912123363209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 944784, while the sum is 50.

The spelling of 9912123363209 in words is "nine trillion, nine hundred twelve billion, one hundred twenty-three million, three hundred sixty-three thousand, two hundred nine".