The greatest 4-digit number with no repeated digits is... 9876
9,999,876 is the greatest seven-digit number using four different digits.
The greatest 3 digit number is 999, and all three digits are the same.
It can have up to 5 digits.
greatest number9999987
98,764
Six.
2
3201
9876543.
9,876,543 is.
987654