Considering the fact that the average density of a black hole inside its Schwarzschild radius is inversely proportional for the square of its mass, supermassive black holes are a lot less dense than stellar black holes. The common density of a 108 M☉ black hole is comparable to that of https://econopass.com/news/science-technology/7-mind-blowing-ways-the-technological-singularity-will-transform-humanity/