A:
Positive:
1 x 212151055 x 424302153 x 400285223 x 95135265 x 80057359 x 590951115 x 190271795 x 11819
Negative:
-1 x -21215105-5 x -4243021-53 x -400285-223 x -95135-265 x -80057-359 x -59095-1115 x -19027-1795 x -11819
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 21,215,105, it is easier to work with a table - it's called factoring from the outside in.
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 | 21,215,105 | |
| -1 | -21,215,105 |
When you multiply two negative numbers together, you get a positive number. That means both the positive and negative numbers are factors of 21,215,105.
Example:
1 x 21,215,105 = 21,215,105
and
-1 x -21,215,105 = 21,215,105
Notice both answers equal 21,215,105
With that explanation out of the way, let's continue. Next, we take the number 21,215,105 and divide it by 2:
21,215,105 ÷ 2 = 10,607,552.5
If the quotient is a whole number, then 2 and 10,607,552.5 are factors. In this case, the quotient is not a whole number. Don't write anything down and try the next divisor.
Here is what our table should look like at this step:
| 1 | 21,215,105 | |
| -1 | -21,215,105 |
Now, we try dividing 21,215,105 by 3:
21,215,105 ÷ 3 = 7,071,701.6667
If the quotient is a whole number, then 3 and 7,071,701.6667 are factors. In this case, the quotient is not a whole number. Don't write anything down and try the next divisor.
Here is what our table should look like at this step:
| 1 | 21,215,105 | |
| -1 | -21,215,105 |
Let's try dividing by 4:
21,215,105 ÷ 4 = 5,303,776.25
If the quotient is a whole number, then 4 and 5,303,776.25 are factors. In this case, the quotient is not a whole number. Don't write anything down and try the next divisor.
Here is what our table should look like at this step:
| 1 | 21,215,105 | |
| -1 | 21,215,105 |
If you did it right, you will end up with this table:
| 1 | 5 | 53 | 223 | 265 | 359 | 1,115 | 1,795 | 11,819 | 19,027 | 59,095 | 80,057 | 95,135 | 400,285 | 4,243,021 | 21,215,105 |
| -1 | -5 | -53 | -223 | -265 | -359 | -1,115 | -1,795 | -11,819 | -19,027 | -59,095 | -80,057 | -95,135 | -400,285 | -4,243,021 | -21,215,105 |
Here are some more numbers to try:
Try the factor calculator