9 (nine)
9 and 99
The largest six-digit number is 999,999. It is the highest value that can be represented with six digits, where each digit is at its maximum of 9. This number is one less than one million, which is the smallest seven-digit number.
9870
The largest single digit composite number is 9. The largest prime number is 17 million digits long. The definition of a composite number is any number that has at least one positive divisor other than one or the number itself (it is not a prime number). The largest composite digit is therefore longer than the largest prime number by at leaf +1.
9
9 and 99
99 + 9 = 108
9
The largest one digit number that has three factors is 9. Its factors are 1, 3, and 9.
It is 9999 (if a one is added, it becomes a five digit number: 9999 + 1 = 10,000)
9870
The largest single digit composite number is 9. The largest prime number is 17 million digits long. The definition of a composite number is any number that has at least one positive divisor other than one or the number itself (it is not a prime number). The largest composite digit is therefore longer than the largest prime number by at leaf +1.
9
9.....??
9
It is: 8
Unless this is a trick question 9995 would be the largest 4 digit number with 5 as one of its digits