arithmetic - it is being given that 5321 is completely divisible by a whole number which of the following numbers is completely divisible by this number - skillgun

Solution: Let 5^32=x.
Then (5^32+1)=(x+1). Let (x+1) be completely divisible by the whole number Y.
then (5^96+1)=[(5^32)^3+1]=>(x^3+1)=(x+1)(x^2-x+1) which is completely divisible by Y.
since (x+1) is divisible by Y.