It depends on the degree of rounding.
To the nearest ten, it is 80005,
To the nearest ten thousand it is 85000,
To the nearest twenty thousand it is 89999.
In order to avoid systemic bias, fives are not rounded up but to to evens as per the IEEE 754 standard.
80000 is, itself, a whole number.
The largest whole number would be 1,999
750000 to 849999
5000
54999.
54999
70
80000
0
600
It could be 599, rounded to the nearest 400.
100