12729991009 has 2 divisors, whose sum is σ = 12729991010. Its totient is φ = 12729991008.

The previous prime is 12729990967. The next prime is 12729991019. The reversal of 12729991009 is 90019992721.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12619152225 + 110838784 = 112335^2 + 10528^2 .

It is a cyclic number.

It is not a de Polignac number, because 12729991009 - 2¹⁹ = 12729466721 is a prime.

It is not a weakly prime, because it can be changed into another prime (12729991019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6364995504 + 6364995505.

It is an arithmetic number, because the mean of its divisors is an integer number (6364995505).

Almost surely, 2^12729991009 is an apocalyptic number.

It is an amenable number.

12729991009 is a deficient number, since it is larger than the sum of its proper divisors (1).

12729991009 is an equidigital number, since it uses as much as digits as its factorization.

12729991009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 183708, while the sum is 49.

The spelling of 12729991009 in words is "twelve billion, seven hundred twenty-nine million, nine hundred ninety-one thousand, nine".