6561697 has 2 divisors, whose sum is σ = 6561698. Its totient is φ = 6561696.

The previous prime is 6561683. The next prime is 6561719. The reversal of 6561697 is 7961656.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6533136 + 28561 = 2556^2 + 169^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6561697 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (6561637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3280848 + 3280849.

It is an arithmetic number, because the mean of its divisors is an integer number (3280849).

Almost surely, 2^6561697 is an apocalyptic number.

It is an amenable number.

6561697 is a deficient number, since it is larger than the sum of its proper divisors (1).

6561697 is an equidigital number, since it uses as much as digits as its factorization.

6561697 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 68040, while the sum is 40.

The square root of 6561697 is about 2561.5809571435. The cubic root of 6561697 is about 187.2141730966.

The spelling of 6561697 in words is "six million, five hundred sixty-one thousand, six hundred ninety-seven".