6561697219669 has 2 divisors, whose sum is σ = 6561697219670. Its totient is φ = 6561697219668.

The previous prime is 6561697219547. The next prime is 6561697219703. The reversal of 6561697219669 is 9669127961656.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5960126347569 + 601570872100 = 2441337^2 + 775610^2 .

It is a cyclic number.

It is not a de Polignac number, because 6561697219669 - 2¹⁵ = 6561697186901 is a prime.

It is a super-3 number, since 3×6561697219669³ (a number of 39 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6561697211669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3280848609834 + 3280848609835.

It is an arithmetic number, because the mean of its divisors is an integer number (3280848609835).

Almost surely, 2^{6561697219669} is an apocalyptic number.

It is an amenable number.

6561697219669 is a deficient number, since it is larger than the sum of its proper divisors (1).

6561697219669 is an equidigital number, since it uses as much as digits as its factorization.

6561697219669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 396809280, while the sum is 73.

The spelling of 6561697219669 in words is "six trillion, five hundred sixty-one billion, six hundred ninety-seven million, two hundred nineteen thousand, six hundred sixty-nine".