Learning lab Math Series

Let P(x) be a polynomial with integral coefficient. If P(x)=0 has atleast 15 distinct integral roots then for any integer n (n should not be root of P(x)=0) then prove that |p(n)|>=8(7!).

2^29 is a nine digit number whose all digits are different.Find the missing digit . (without solving the value of 2^29)