6560017781 has 2 divisors, whose sum is σ = 6560017782. Its totient is φ = 6560017780.

The previous prime is 6560017759. The next prime is 6560017801. The reversal of 6560017781 is 1877100656.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5926690225 + 633327556 = 76985^2 + 25166^2 .

It is a cyclic number.

It is not a de Polignac number, because 6560017781 - 2³⁰ = 5486275957 is a prime.

It is a super-2 number, since 2×6560017781² = 86067666574072327922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6560013781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3280008890 + 3280008891.

It is an arithmetic number, because the mean of its divisors is an integer number (3280008891).

Almost surely, 2^6560017781 is an apocalyptic number.

It is an amenable number.

6560017781 is a deficient number, since it is larger than the sum of its proper divisors (1).

6560017781 is an equidigital number, since it uses as much as digits as its factorization.

6560017781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 70560, while the sum is 41.

The square root of 6560017781 is about 80993.9366928167. The cubic root of 6560017781 is about 1871.9820159723.

The spelling of 6560017781 in words is "six billion, five hundred sixty million, seventeen thousand, seven hundred eighty-one".