9,876,543 is.
9,999,876 is the greatest seven-digit number using four different digits.
greatest number9999987
98
987654
3201
The greatest 4-digit number with no repeated digits is... 9876
9876 and 1234
That would be 99987.
999987
99,999,987
99,999,876
The greatest 9-digit number using three different digits is 999888777, formed by using the digits 9, 8, and 7 in descending order. The smallest 9-digit number using three different digits is 100000000, created with the digits 1, 0, and 0. This arrangement ensures that the number starts with 1, followed by the zeros to maintain the smallest value.