6661772774309 has 2 divisors, whose sum is σ = 6661772774310. Its totient is φ = 6661772774308.

The previous prime is 6661772774297. The next prime is 6661772774311. The reversal of 6661772774309 is 9034772771666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4900565093284 + 1761207681025 = 2213722^2 + 1327105^2 .

It is a cyclic number.

It is not a de Polignac number, because 6661772774309 - 2³⁶ = 6593053297573 is a prime.

Together with 6661772774311, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6661772774369) 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, 3330886387154 + 3330886387155.

It is an arithmetic number, because the mean of its divisors is an integer number (3330886387155).

Almost surely, 2^{6661772774309} is an apocalyptic number.

It is an amenable number.

6661772774309 is a deficient number, since it is larger than the sum of its proper divisors (1).

6661772774309 is an equidigital number, since it uses as much as digits as its factorization.

6661772774309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 112021056, while the sum is 65.

The spelling of 6661772774309 in words is "six trillion, six hundred sixty-one billion, seven hundred seventy-two million, seven hundred seventy-four thousand, three hundred nine".