This paper considered the concepts of monophonic, closed monophonic, and minimal closed monophonic numbers of a connected graph . It was shown that any positive integers , and satisfying the conditions that , and are realizable as the monophonic number, closed monophonic number, -diameter, and order, respectively, of a connected graph. Also, any positive integers , and with , and are realizable as the closed monophonic number, minimal closed monophonic number, -diameter, and order, respectively, of a connected graph. Further, the closed monophonic number of the composition of connected graphs was also determined.