Hummer scored nine points during a 17-5 run for the Tigers (11-7, 4-0) at the end of the first half that produced a 29-17 halftime advantage.
Princeton, which shot 54.8 percent (23 of 42) and made 8 of 13 from 3-point range, never led by fewer than 12 in the second half.
Koon and T.J. Bray, who finished with 14 points, each made 6 of 7 shots for Princeton, and Hummer was 6 of 10.
Hummer now has 1,455 career points, good for fourth on Princeton's all-time list. He passed Craig Robinson, the brother-in-law of President Obama, who had been fifth, and Pete Campbell.
Rafael Maia scored 19 points for the Bears (8-11, 2-3), who shot 38 percent (19 of 50), including 1 of 12 on 3-pointers.
Maryland point guard Melo Trimble, considered a lock to leave the program before struggling in the second half last season, has withdrawn from the NBA draft and will return for his junior season.
Louisville's Chinanu Onuaku, who recently underwent a medical procedure to correct a heart rhythm issue detected during the combine, will keep his name in the NBA draft pool.
Andrew White III will return to the Nebraska men's basketball team next season after removing his name from the NBA draft.