Obscene number (5)
I believe the answer is:
gross
I believe this clue is a double definition.
'obscene' is the first definition.
(thesaurus)
'number' is the second definition.
(gross is a kind of whole number)
(Other definitions for gross that I've seen before include "domestic product may be?" , "A dozen dozen - that's vulgar" , "Rank" , "Earn" , "large total before deductions" .)