Assuming all digits are equally likely, then it is 0.9395.
However, that assumption is flawed since some numbers begin with 0. Some sequences are reserved and so on. So the distribution of numbers is NOT truly random and the above answer depends on all seven digit numbers being equally likely..
2016/4000 = 0.504
The largest number with no repeated digits is 9,876,543,210 although it is 10 digits long, the largest 3 digit number with no repeated digits is 987
The largest ten digit number with no repeated digits is '9876543210'.
The greatest 4-digit number with no repeated digits is... 9876
987654
It is possible to create a 3-digit number, without repeated digits so the probability is 1.
2016/4000 = 0.504
The largest ten digit number with no repeated digits is '9876543210'.
The largest number with no repeated digits is 9,876,543,210 although it is 10 digits long, the largest 3 digit number with no repeated digits is 987
The largest ten digit number with no repeated digits is '9876543210'.
The greatest 4-digit number with no repeated digits is... 9876
987654
1023456789
10234567
infinite
The largest ten digit number with no repeated digits is '9876543210'.
Since there are only five different digits, a 6-digit number can only be generated if a digit can be repeated. If digits can be repeated, the smallest 6-digit number is 111111.