A:
Positive:
1 x 211002055 x 42200417 x 301431535 x 60286361 x 345905305 x 69181427 x 494152135 x 9883
Negative:
-1 x -21100205-5 x -4220041-7 x -3014315-35 x -602863-61 x -345905-305 x -69181-427 x -49415-2135 x -9883
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 21,100,205, 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 | 21,100,205 | |
| -1 | -21,100,205 |
When you multiply two negative numbers together, you get a positive number. That means both the positive and negative numbers are factors of 21,100,205.
Example:
1 x 21,100,205 = 21,100,205
and
-1 x -21,100,205 = 21,100,205
Notice both answers equal 21,100,205
With that explanation out of the way, let's continue. Next, we take the number 21,100,205 and divide it by 2:
21,100,205 ÷ 2 = 10,550,102.5
If the quotient is a whole number, then 2 and 10,550,102.5 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 | 21,100,205 | |
| -1 | -21,100,205 |
Now, we try dividing 21,100,205 by 3:
21,100,205 ÷ 3 = 7,033,401.6667
If the quotient is a whole number, then 3 and 7,033,401.6667 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 | 21,100,205 | |
| -1 | -21,100,205 |
Let's try dividing by 4:
21,100,205 ÷ 4 = 5,275,051.25
If the quotient is a whole number, then 4 and 5,275,051.25 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 | 21,100,205 | |
| -1 | 21,100,205 |
If you did it right, you will end up with this table:
| 1 | 5 | 7 | 35 | 61 | 305 | 427 | 2,135 | 9,883 | 49,415 | 69,181 | 345,905 | 602,863 | 3,014,315 | 4,220,041 | 21,100,205 |
| -1 | -5 | -7 | -35 | -61 | -305 | -427 | -2,135 | -9,883 | -49,415 | -69,181 | -345,905 | -602,863 | -3,014,315 | -4,220,041 | -21,100,205 |
Here are some more numbers to try:
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