What number president?

[Fujibei]

If you don't know Barack Obama is the 44th president of the U.S.A., how do you ask?
Do the following questions work?

1. What number president is Barack Obama?
2. How many presidents werer there before Barack Obama?

[phrasemix]

Hi Fujibei,
That's a good question. (By the way, when someone says "That's a good question" it usually means that the question is difficult to answer.)

I think I would have trouble forming this question. #1 doesn't make a lot of sense unless the person you're asking already knows what you're trying to say. So #2 is a good way to get around the fact that there's no clear grammatical structure for this.

[Vega]

This is what suggested me Google Dictionary.

What the bill, president Barack Obama?

[PureGuava]

If you don't know Barack Obama is the 44th president of the U.S.A., how do you ask?
Do the following questions work?

1. What number president is Barack Obama?
2. How many presidents werer there before Barack Obama?

"Is Barack (Obama) the 44th president (of the United States)?"

The words in parenthesis are words that you wouldn't necessarily use, since they are assumed/understood.