Extract the answer to the question from the following context. Question: What number represents the players that have been honored regarding their careers after leaving Notre Dame? Context: Notre Dame rose to national prominence in the early 1900s for its Fighting Irish football team, especially under the guidance of the legendary coach Knute Rockne. The university's athletic teams are members of the NCAA Division I and are known collectively as the Fighting Irish. The football team, an Independent, has accumulated eleven consensus national championships, seven Heisman Trophy winners, 62 members in the College Football Hall of Fame and 13 members in the Pro Football Hall of Fame and is considered one of the most famed and successful college football teams in history. Other ND teams, chiefly in the Atlantic Coast Conference, have accumulated 16 national championships. The Notre Dame Victory March is often regarded as the most famous and recognizable collegiate fight song.
The answer to this question is:
13