That depends what you are rounding to:
It would round to 5000.
5000
To the nearest thousand, 5000
As there is a zero in the hundreds position, it will round down to 5000.
5000
It would round to 5000.
5000
5000 would round to 5000.
To the nearest thousand, 5000
As there is a zero in the hundreds position, it will round down to 5000.
5000
5000
6,000
5000
To the nearest thousand, it is 5000.
As the thousands digit is a 4, it will round down to zero.
There are a lot more than 5. There are 9 of them if you round to the nearest tens not including 5000