What number between 3000 and 4000 that is nearer to 4000?

The number between 3000 and 4000 that is nearer to 4000 is 3999. This number is only 1 unit away from 4000, whereas the closest number to 3000, which is 3000 itself, is 999 units away from 4000. Therefore, 3999 is the number that is closer to 4000 in this range.