It is 90001.
It isn't, it's the largest.
You get the largest number if you sort the digits, from largest to smallest.
The smallest positive integer six-digit number is 100000.
The smallest six-digit even number is 100,000
123456.
100,000
99999
The largest six digit number is 999,999.
The largest 6 digit even number is 999998
100000
100,000