More billionaires went to the University of Pennsylvania for their undergraduate degrees than any other college in the world, according to a new report from Wealth-X.

25 current billionaires received their bachelor's degrees at Penn, the most of any school on Wealth-X's list. The only other colleges to produce similar numbers were Harvard University — with 22 undergrad alum billionaires — and Yale University — with 20.

American universities dominated the undergraduate alumni billionaires list, representing all but four spots in the top 20, including the first eight positions.

Here are the 20 universities with the most billionaire undergraduate alumni and how many alumni they have, via Wealth-X:

1. University of Pennsylvania — 25

2. Harvard University — 22

3. Yale University — 20

4. University of Southern California — 16

5. Cornell University — 14

5. Princeton University — 14

5. Stanford University — 14

8. University of California, Berkeley — 12

8. University of Mumbai (India) — 12

10. London School of Economics (United Kingdom) — 11

10. Lomonosov Moscow State University (Russia) — 11

12. Dartmouth College — 10

12. University of Michigan — 10

12. University of Texas — 10

15. Duke University — 9

15. New York University — 9

17. Brown University — 8

17. Columbia University — 8

19. Massachusetts Institute of Technology — 7

20. Eth Zurich (Switzerland) — 6

Last year's Wealth-X billionaire census looked at universities with the most billionaire alumni of both undergraduate and graduate programs. Harvard topped that list, with 52 billionaire alumni. Penn came in second, with 28.