What is the greatest possible prime you must consider to test whether 8243 is prime?

I'll consider just 3

Step-by-step explanation:

To check if a number is a prime number it has to undergo series of division.

Let's not forget that a prime number is a number divisible by only itself and one

So for my argument.

2 cannot the number

3 cannot also divide the number

5 and 7 too cannot Divide the number.

I'll consider just 3 as the highest prime number to divide it