From Einstein’s “Relativity” what is the shape and size of the universe?

In Einstein’s 1920 book he states: “The results of calculation indicates that if matter is distributed uniformly, the universe would necessarily be spherical or elliptical. The non-uniform distribution would make it quasi-spherical. For the radius R he gets 2/kp where for cgs 2/k = 1.08E27 and p is the average density of matter.

Does anyone know the answer for R? In addition did his later work change his ideas about a spherical universe? It is my own belief that his answer is correct and we live on a spherical plane upon which the galaxies reside thus it is a bumpy plane. For my own theory I calculate 1.304E26 meters and I wonder what Einstein’s answer was.