The approximate scale of the largest known supermassive black hole (S5 0014+81) compared to the size of our solar system.

an awesome beast indeed ... I did a little reading on this and it seems like 280 light-years from this monster and you would receive the same amount of radiant energy than the earth receives from the sun ... so a 280 light-year radius habitable zone??
You would still recieve radiant energy, the image below shows how it looks like if it's located just 280 light years away, it would shine as brightly as our sun does in the sky. So yes, but very unhealthy if you're exposed to it.

The S5 0014+81 is about 10,000 times more massive than the black hole at the center of our galaxy, or equivalent to 40 billion solar masses.
The Schwarzschild radius (event horizon) of this black hole is 118.35 billion kilometers, giving a diameter of 236.7 billion kilometers, 1,600 astronomical units, or about 40 times the radius of Pluto's orbit, and has a mass equivalent to four Large Magellanic Clouds.