Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Radius
PRIM_SPHERE_RAD
Parameter: Segments
PRIM_SPHERE_SUB
Parameter: Type
PRIM_SPHERE_TYPE
Parameter: Render Perfect
PRIM_SPHERE_PERFECT
Parameter: Switch to Updated Sphere
PRIM_SPHERE_SWITCH_TO_UPDATED