The 26,199 mile radius from the center of the Earth to geosynchronous orbit, minus the Earth's radius of 3,963 miles at the equator, puts the satellites 22,236 miles above mean sea level. I knew they were 22,000 some miles away but had to look it up. If Apophis passes 18,600 miles away from the Earth that would put it 3,636 miles inside of geosynchronous orbit. It would only be about 2.35 Earth diameters away, whether you go by the equatorial diameter of 7,926 miles, the mean diameter of 7,918 miles, or the polar diameter of 7,900 miles. 2.35 Earth diameters is microscopic on the scale of the universe. In other words, way too close for comfort.
And that's if those calculations prove correct and it doesn't get a little gravitational nudge. The universe contains 4.9% ordinary matter, and the other 95.1% is dark energy plus dark matter. Did the calculations for Apophis' trajectory take all of that invisible matter and energy into account? Is the theory of of dark matter and dark energy right in the first place? No one knows for sure.