In the everyday decimal system of writing numbers . . .
-- The largest two digits are 8 and 9.
-- Their product is 72.
-- 10 less than that is 62 .
9876 is the largest four digit number you can make if all the digits must be different.
The largest 3 digit number whose digits are all primes is 777. The largest 3 digit number with different prime digits is 753.
9876543
The largest 4-digit number with two different digits is 9998. Its successor is the next number, which is 9999. However, 9999 has only one digit (9), so we need to find the next valid 4-digit number with two different digits. This number is 10000, which is technically a 5-digit number, so the largest valid number with two different digits before 9999 is 9998, and its successor cannot be a 4-digit number with two different digits. Thus, there is no valid successor that meets the criteria.
9,876
-109
9876 is the largest four digit number you can make if all the digits must be different.
The largest 3 digit number whose digits are all primes is 777. The largest 3 digit number with different prime digits is 753.
9876543
9876 (:
The largest ten digit number with no repeated digits is '9876543210'.
The largest 4-digit number with two different digits is 9998. Its successor is the next number, which is 9999. However, 9999 has only one digit (9), so we need to find the next valid 4-digit number with two different digits. This number is 10000, which is technically a 5-digit number, so the largest valid number with two different digits before 9999 is 9998, and its successor cannot be a 4-digit number with two different digits. Thus, there is no valid successor that meets the criteria.
61 is prime. You cannot make 61 by multiplying four digits.
19
The largest integer that is not the product of two or more different primes would be the largest prime number. Because there are an infinite number of prime numbers, there is no largest integer that is not the product of two or more different primes.
> 9999876 Actually, 9999876 has four different digits (6, 7, 8, 9). The largest 7-digit number with three different digits is 9999987.
9,876