Actually, the two-digit number 1 is not divisible by 9. In order for a number to be divisible by 9, the sum of its digits must be divisible by 9. The number 1 only contains a single digit and does not meet this criterion.
To determine if a two-digit number is divisible by 9, we need to check if the sum of its digits is divisible by 9. Since we have a one-digit number (1), we can conclude that it is not divisible by 9.
Actually, the statement you provided is not true. The number 1 is not divisible by 9. To be divisible by 9, a number must have a sum of its digits that is divisible by 9. For example, 18 is divisible by 9 because 1 + 8 = 9, but the number 1 itself is not divisible by 9.
