with data as (
	select '4' [val] union all
	select '530' union all
	select '117,123,128,170' union all
	select '93,103' union all
	select '117,122,164' union all
	select '8,117,152' union all
	select '117,125,194,626,650' union all
	select '1,63' union all
	select '1,5' union all
	select '720,783,992' union all
	select '720,773,810,992'
)
select 
	iif(charindex(',',val)=0,val,reverse(left(reverse(val),charindex(',',reverse(val))-1)))
from data