The answer depends on the units used for 24000. It should be obvious to anybody that the answers for 24000 ounces and 24000 grams will be very different.
24000
It is: 24000
To the nearest thousand, 24000
24400
23950 to 24049 inclusive
24000
24000
24000
24000
24000
24000
24000
24000
It is: 24000
To the nearest thousand, 24000
25000
24000