56 if digits may be repeated.
18 if they may not be.
Note: I didn't allow any leading zeros.
With 123 digits you can make 123 one-digit numbers.
Not sure what a "didget" is. It is possible to make 18 5-digit numbers.
Just one. In a combination, the order of the digits does not matter.
8
5040
With 123 digits you can make 123 one-digit numbers.
12 numbers
Not sure what a "didget" is. It is possible to make 18 5-digit numbers.
Just one. In a combination, the order of the digits does not matter.
8
720 of them.
162
5040
6, as long as they are all different
There are 7,290 different 4-digit numbers that can be formed from the digits 1-9 without repetition.
12,13,14 21,23,24 31,32,34 43,42,41 12 two-digit numbers
There are no three didgit numbers but there are 63 three digit numbers.