## Each digit of a 9 digit number is 1 it is multiplied by itself. what is the sum of the digits of the resulting number

- 67
- 80
- 81
- 100

To find the sum of the digits of the result when the number 111111111 is multiplied by itself (111111111 * 111111111), we can calculate the product and then sum the resulting digits.

The product of 111111111 * 111111111 is 12345678987654321.

To find the sum of the digits in this product, we add each digit together:

1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 8 + 7 + 6 + 5 + 4 + 3 + 2 + 1 = 81

Therefore, the sum of the digits of the resulting number is 81.

**The correct answer is: 81.**