I learned this interesting factoid in an astrophysics class. All data is from Wolfram Alpha: Mass of universe: 3 * 10^52 kg Schwarzschild radius for that mass

I learned this interesting factoid in an astrophysics class. All data is from Wolfram Alpha: Mass of universe: 3 * 10^52 kg Schwarzschild radius for that mass: 4.455 * 10^25 meters Volume of sphere with that radius: 3.704 * 10^77 m^3 Density = mass / volume = 8.099 * 10^-29 g/cm^3, or roughly 8 times the approximate universe density I think it's interesting that a universe-sized black hole would be a mass within an order of magnitude of the universe's mass.