12210642721 has 2 divisors, whose sum is σ = 12210642722. Its totient is φ = 12210642720.

The previous prime is 12210642671. The next prime is 12210642739. The reversal of 12210642721 is 12724601221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11074615696 + 1136027025 = 105236^2 + 33705^2 .

It is an emirp because it is prime and its reverse (12724601221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12210642721 - 2¹³ = 12210634529 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12210642721.

It is not a weakly prime, because it can be changed into another prime (12210642761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6105321360 + 6105321361.

It is an arithmetic number, because the mean of its divisors is an integer number (6105321361).

Almost surely, 2^12210642721 is an apocalyptic number.

It is an amenable number.

12210642721 is a deficient number, since it is larger than the sum of its proper divisors (1).

12210642721 is an equidigital number, since it uses as much as digits as its factorization.

12210642721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2688, while the sum is 28.

The spelling of 12210642721 in words is "twelve billion, two hundred ten million, six hundred forty-two thousand, seven hundred twenty-one".