4
No US president is known to have had epilepsy.
Around15
2 there are two Presidents. President Franklin Pierce and President Franklin D. Roosevelt.
None you have to be a American citizen to be President.
8
George Washington was president from 1789-1797 and about 16 or 17 presidents served after him up to 1869.
Presidents of what? In the USA, only people who were born in the US or its territories are allowed to be President.
It depends what time you're asking about. There were many presidents at many times.
Certainly! There are many Vice-Presidents that have served as President, both because of the death of a president and because they were elected.
The US at one time may only have one president. The total number of presidents that the US has had if you count the current one is 44.
As of 1976, Gerald Ford was the current and 38th President.