Assuming whole numbers and a leading zero does not count: 10,234,567
987654321
10234567
4321
There are twelve possible solutions using the rule you stated.
98765432
10234567
987654321
4321
9,876,543
There are twelve possible solutions using the rule you stated.
98765432
The smallest possible 9 digit number (assuming negatives are not allowed) is 102,345,678 in which 5 is in the thousands' place.
123,456,789
9876543
9876543
It is 98765.
The least possible integer is -98765432. The least possible positive integer is 10234567.