12721235689 has 2 divisors, whose sum is σ = 12721235690. Its totient is φ = 12721235688.

The previous prime is 12721235641. The next prime is 12721235693. The reversal of 12721235689 is 98653212721.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12364328025 + 356907664 = 111195^2 + 18892^2 .

It is a cyclic number.

It is not a de Polignac number, because 12721235689 - 2¹⁹ = 12720711401 is a prime.

It is not a weakly prime, because it can be changed into another prime (12721235089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6360617844 + 6360617845.

It is an arithmetic number, because the mean of its divisors is an integer number (6360617845).

Almost surely, 2^12721235689 is an apocalyptic number.

It is an amenable number.

12721235689 is a deficient number, since it is larger than the sum of its proper divisors (1).

12721235689 is an equidigital number, since it uses as much as digits as its factorization.

12721235689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362880, while the sum is 46.

The spelling of 12721235689 in words is "twelve billion, seven hundred twenty-one million, two hundred thirty-five thousand, six hundred eighty-nine".