The most popular jersey numbers in basketball are 7,12, 23, 32, and 33. Currently, the most popular jersey number in the NBA is 7. 12 is the most popular jersey number in NBA history.
As of right now more current NBA players wear the number 7 than any other number. The number 12 has been worn by more players than any other number in the history of the NBA Over three-hundred sixty NBA players have worn the number 12. Other popular basketball jersey numbers are 23, 32, and 33. These numbers are popular, in part, because some of the most famous basketball players in history wore these numbers. The success of the players who wore those numbers impacted and increased sales and exposure for those numbers. It also inspired younger players to choose those numbers in an effort to emulate the players that wore those jersey numbers.
Another factor to consider is that the NCAA and most high school leagues do not allow players to wear jerseys with a digit higher than five. The rule limits the pool of eligible jersey numbers to 36. Most players grow attached to a number and prefer to keep that number from high school, through college, and into the NBA.