Cosmic Numbers

[bubbo2000]

12 is 6, 6 is 3, 3 is 5, and 5 is 4, 4 is cosmic
9 is 4 and 4 is cosmic
1 is 3, 3 is 5, and 5 is cosmic.

Whats the rule? What other cosmic numbers are there?

 

[triggerfinger12]

50 is 5, 5 is 4, 4 is cosmic