  LLet $x>1$ be a large number. This note shows that the largest prime factor
of the quadratic product $\prod_{x\leq n\leq 2x}\left(n^2+1 \right)$ satisfies
the relation $p \geq x^{3/2}$ as $x$ tends to infinity. This improves the
current estimate $p \geq x^{1.279}$. In addition, it is shown that $n^2+1 $ has
a large prime divisor in the interval $ p\in [x^{2-o(1)},x^2] $ for some $
n\geq x^{1-o(1)}$.
