# Math Help - Prime number

1. ## Prime number

1 ) Calculate :
2 ) Deduct : the number 103121 is prime number.

2. for the first one

$(x^3+2x+1)(x^2+1)$

$x^2(x^3+2x+1)+1(x^3+2x+1)$

3. $103121=101\times 1021$

A answer without calculators will be highly appreciated..
I used a calculator

4. ; if x = 10, then (10^3 + 2(10) + 1)(10^2 + 1) = (1021)(101) = 103121