How many teams in the NBA have retired number 23?

LeBron James will join this list of NBA players with numbers retired by multiple teams – NBC Los Angeles

Which jersey numbers should actually be retired for the Utah Jazz? - SLC Dunk

LeBron James will switch back to jersey number 23 'out of respect' for the late Bill Russell

LeBron on course to join legends with jerseys retired by multiple teams

Jimmy Butler reveals Pat Riley was willing to unretire Michael Jordan's No. 23 and let him wear it with Miami Heat - Heat Nation

Pat Riley Surprisingly Retiring Michael Jordan's Jersey For Heat Resurfaces as Jimmy Butler Justifies Not Wearing #23 - The SportsRush

List of National Basketball Association retired numbers - Wikipedia