The answer depends on the degree of rounding. To the nearest 14000, 20999.99... will round to 14000 (21000 will round tro 28000) On the other hand, to the nearest unit, 14000.51 will not round to 14000 but to 14001.
13999 and 13998
The biggest whole number that can be rounded off to 14000 to the nearest 14000 is 20999. To the nearest 14000, all numbers such that 7000 ≤ the number < 21000 will round to 14000.
14000
2311
As a product of its prime factors: 2*2*2*2*5*5*5*7 = 14000
14000
3500
7.3 and 6.5
6.012 6.009
8.216 or 8.2237 are two possible numbers.
28 and 29