How do I find the factor combinations of the number 81,223,320?
Unfortunately, there's not simple formula to identifying all of the factors of a number and it can be a tedious process when trying to identify the divisors of larger numbers.
To find the factor combinations of the number 81,223,320, it is easier to work with a table - it's called factoring from the outside in.
Outside in Factoring
We start by creating a table and writing 1 on the left side and then the number we're trying to find the factors for on the right side in a table. Then, below that, write the numbers as a negative as well.
1 |
|
81,223,320 |
-1 |
|
-81,223,320 |
Why are the negative numbers included?
When you multiply two negative numbers together, you get a positive number. That means both the positive and negative numbers are factors of 81,223,320.
Example:
1 x 81,223,320 = 81,223,320
and
-1 x -81,223,320 = 81,223,320
Notice both answers equal 81,223,320
With that explanation out of the way, let's continue. Next, we take the number 81,223,320 and divide it by 2:
81,223,320 ÷ 2 = 40,611,660
If the quotient is a whole number, then 2 and 40,611,660 are factors. In this case, the quotient is a whole number. Write them in the table inside the other two factors like the below example. Don't forget to write the negative numbers too!
Here is what our table should look like at this step:
Now, we try dividing 81,223,320 by 3:
81,223,320 ÷ 3 = 27,074,440
If the quotient is a whole number, then 3 and 27,074,440 are factors. In this case, the quotient is a whole number. Write them in the table inside the other two factors like the below example. Don't forget to write the negative numbers too!
Here is what our table should look like at this step:
Let's try dividing by 4:
81,223,320 ÷ 4 = 20,305,830
If the quotient is a whole number, then 4 and 20,305,830 are factors. In this case, the quotient is a whole number. Write them in the table inside the other two factors like the below example. Don't forget to write the negative numbers too!
Here is what our table should look like at this step:
Keep dividing by the next highest number until you cannot divide anymore.
If you did it right, you will end up with this table:
More Examples
Here are some more numbers to try:
Try the
factor calculator