A:
Positive:
1 x 211151055 x 422302111 x 191955517 x 124206555 x 38391185 x 248413121 x 174505187 x 112915605 x 34901935 x 225832053 x 102852057 x 10265
Negative:
-1 x -21115105-5 x -4223021-11 x -1919555-17 x -1242065-55 x -383911-85 x -248413-121 x -174505-187 x -112915-605 x -34901-935 x -22583-2053 x -10285-2057 x -10265
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 21,115,105, 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 | 21,115,105 | |
| -1 | -21,115,105 |
When you multiply two negative numbers together, you get a positive number. That means both the positive and negative numbers are factors of 21,115,105.
Example:
1 x 21,115,105 = 21,115,105
and
-1 x -21,115,105 = 21,115,105
Notice both answers equal 21,115,105
With that explanation out of the way, let's continue. Next, we take the number 21,115,105 and divide it by 2:
21,115,105 ÷ 2 = 10,557,552.5
If the quotient is a whole number, then 2 and 10,557,552.5 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 | 21,115,105 | |
| -1 | -21,115,105 |
Now, we try dividing 21,115,105 by 3:
21,115,105 ÷ 3 = 7,038,368.3333
If the quotient is a whole number, then 3 and 7,038,368.3333 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 | 21,115,105 | |
| -1 | -21,115,105 |
Let's try dividing by 4:
21,115,105 ÷ 4 = 5,278,776.25
If the quotient is a whole number, then 4 and 5,278,776.25 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 | 21,115,105 | |
| -1 | 21,115,105 |
If you did it right, you will end up with this table:
| 1 | 5 | 11 | 17 | 55 | 85 | 121 | 187 | 605 | 935 | 2,053 | 2,057 | 10,265 | 10,285 | 22,583 | 34,901 | 112,915 | 174,505 | 248,413 | 383,911 | 1,242,065 | 1,919,555 | 4,223,021 | 21,115,105 |
| -1 | -5 | -11 | -17 | -55 | -85 | -121 | -187 | -605 | -935 | -2,053 | -2,057 | -10,265 | -10,285 | -22,583 | -34,901 | -112,915 | -174,505 | -248,413 | -383,911 | -1,242,065 | -1,919,555 | -4,223,021 | -21,115,105 |
Here are some more numbers to try:
Try the factor calculator