100,000
24
There are 504 such numbers.
823543
6
9999
100,000
512
24
There are 504 such numbers.
There are 60480 numbers.
823543
6
840
There are 5! = 120 such numbers.
The number 1234567890 can create about 39 of 40 4 digit numbers.
5040 different 4 digit numbers can be formed with the digits 123456789. This is assuming that no digits are repeated with each combination.