6×6 isn’t a number, hence no problem in saying it.
as a matter of fact if someone asked you what’s tonight’s number and you just say 36, many poskum say you can still say the bracha as all you said was a number.
imagine someone owes you 36.00 and he asks you how much do i owe you. you’ll respond with 36, ooops i can’t count sefira tonight.
so in order to do it right you have to say “tonight” is number 36