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 number that can be rounded off to 14,000 is 13,500. When rounding to the nearest thousand, any number greater than or equal to 13,500 would round up to 14,000. Numbers below 13,500 would round down to 13,000.
14000
14000
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
14000
8.216 or 8.2237 are two possible numbers.