| 1210 |
| 2020 |
| 21200 |
| 3211000 |
| 42101000 |
| 521001000 |
| 6210001000 |
This is how far you can go with decimal numbers. A digit on the 11th position makes no sense.
If, on the other hand, you accept bases greater than 10, the following numbers are possible:
| 821000001000 |
| 9210000001000 |
and if you accept digits greater than 9, there is no limit:
| A2100000001000 |
| B21000000001000 |
| ... |
Haven't you guessed the system yet? Take 1210. It has 1 zero, 2 ones, 1 two and 0 threes - 1 2 1 0.