A solid conducting sphere has net positive charge and radius $\backslash ($ R$=0\mathrm{.}500\backslash$mathrm$\{$~m$\}\backslash ).$ At a point $1\mathrm{.}20$ m from the center of the sphere, the electric potential due to the charge on the sphere is $21\mathrm{.}0$ V $.$ Assume that $\backslash ($ V$=0\backslash )$ at an infinite distance from the sphere.

Part A

What is the electric potential at the center of the sphere?

Express your answer with the appropriate units.