853
this was a trick question...
679 is the product of the largest single-digit prime number and the largest two-digit prime number.
997 is the largest 3-digit prime number.
You could say -9 or 0 for the smallest, depending on whether you want to include negative numbers or not. 9 would be the largest one digit number.
9
73 is the largest two-digit number that is prime and has prime numbers for both of its digits.
900 It is the only three digit number with a nine in the numbers place
73 is the largest 2 digit number that is both prime and has prime numbers for both of its digits.
9,876 since these are the largest single digit numbers that can be done without repeat.
There can only be one largest two-digit prime number.
874321 is the largest number made from all these digits.
52,355,500 is an eight-digit number.
9,876,543,210 9876543210