A:
Positive:
1 x 216612555 x 43322517 x 309446511 x 196920535 x 61889355 x 39384177 x 281315385 x 56263
Negative:
-1 x -21661255-5 x -4332251-7 x -3094465-11 x -1969205-35 x -618893-55 x -393841-77 x -281315-385 x -56263
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 21,661,255, 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 | 21,661,255 | |
| -1 | -21,661,255 |
When you multiply two negative numbers together, you get a positive number. That means both the positive and negative numbers are factors of 21,661,255.
Example:
1 x 21,661,255 = 21,661,255
and
-1 x -21,661,255 = 21,661,255
Notice both answers equal 21,661,255
With that explanation out of the way, let's continue. Next, we take the number 21,661,255 and divide it by 2:
21,661,255 ÷ 2 = 10,830,627.5
If the quotient is a whole number, then 2 and 10,830,627.5 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 | 21,661,255 | |
| -1 | -21,661,255 |
Now, we try dividing 21,661,255 by 3:
21,661,255 ÷ 3 = 7,220,418.3333
If the quotient is a whole number, then 3 and 7,220,418.3333 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 | 21,661,255 | |
| -1 | -21,661,255 |
Let's try dividing by 4:
21,661,255 ÷ 4 = 5,415,313.75
If the quotient is a whole number, then 4 and 5,415,313.75 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 | 21,661,255 | |
| -1 | 21,661,255 |
If you did it right, you will end up with this table:
| 1 | 5 | 7 | 11 | 35 | 55 | 77 | 385 | 56,263 | 281,315 | 393,841 | 618,893 | 1,969,205 | 3,094,465 | 4,332,251 | 21,661,255 |
| -1 | -5 | -7 | -11 | -35 | -55 | -77 | -385 | -56,263 | -281,315 | -393,841 | -618,893 | -1,969,205 | -3,094,465 | -4,332,251 | -21,661,255 |
Here are some more numbers to try:
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