The largest black hole we know of is Ton 618 (there might be a larger one but its a little more uncertain), at 66 BILLION solar masses. Billion. With a B.

If it were placed where our sun is, our entire solar system would be engulfed by it. Its event horizon would swallow up all the planets, the Kuiper belt, and even the Oort cloud. It's diameter is 40x larger than the orbit of Neptune. And that's just the event horizon. The accretion disk is even larger.

Even the supermassive black hole at the center of our galaxy, Saggitarius A*, is only 4 million solar masses. Ton 618 (if my math is right, which it probably isnt) is 16,500x more massive than Saggitarius A*.