6563663681 has 2 divisors, whose sum is σ = 6563663682. Its totient is φ = 6563663680.

The previous prime is 6563663627. The next prime is 6563663737. The reversal of 6563663681 is 1863663656.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5020431025 + 1543232656 = 70855^2 + 39284^2 .

It is a cyclic number.

It is not a de Polignac number, because 6563663681 - 2²² = 6559469377 is a prime.

It is a super-2 number, since 2×6563663681² = 86163361834556939522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6563660681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3281831840 + 3281831841.

It is an arithmetic number, because the mean of its divisors is an integer number (3281831841).

Almost surely, 2^6563663681 is an apocalyptic number.

It is an amenable number.

6563663681 is a deficient number, since it is larger than the sum of its proper divisors (1).

6563663681 is an equidigital number, since it uses as much as digits as its factorization.

6563663681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2799360, while the sum is 50.

The square root of 6563663681 is about 81016.4408067893. The cubic root of 6563663681 is about 1872.3287525946.

The spelling of 6563663681 in words is "six billion, five hundred sixty-three million, six hundred sixty-three thousand, six hundred eighty-one".