A:
Positive:
1 x 212077455 x 424154913 x 163136565 x 32627383 x 255515415 x 511031079 x 196553931 x 5395
Negative:
-1 x -21207745-5 x -4241549-13 x -1631365-65 x -326273-83 x -255515-415 x -51103-1079 x -19655-3931 x -5395
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 21,207,745, 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 | 21,207,745 | |
| -1 | -21,207,745 |
When you multiply two negative numbers together, you get a positive number. That means both the positive and negative numbers are factors of 21,207,745.
Example:
1 x 21,207,745 = 21,207,745
and
-1 x -21,207,745 = 21,207,745
Notice both answers equal 21,207,745
With that explanation out of the way, let's continue. Next, we take the number 21,207,745 and divide it by 2:
21,207,745 ÷ 2 = 10,603,872.5
If the quotient is a whole number, then 2 and 10,603,872.5 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 | 21,207,745 | |
| -1 | -21,207,745 |
Now, we try dividing 21,207,745 by 3:
21,207,745 ÷ 3 = 7,069,248.3333
If the quotient is a whole number, then 3 and 7,069,248.3333 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 | 21,207,745 | |
| -1 | -21,207,745 |
Let's try dividing by 4:
21,207,745 ÷ 4 = 5,301,936.25
If the quotient is a whole number, then 4 and 5,301,936.25 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 | 21,207,745 | |
| -1 | 21,207,745 |
If you did it right, you will end up with this table:
| 1 | 5 | 13 | 65 | 83 | 415 | 1,079 | 3,931 | 5,395 | 19,655 | 51,103 | 255,515 | 326,273 | 1,631,365 | 4,241,549 | 21,207,745 |
| -1 | -5 | -13 | -65 | -83 | -415 | -1,079 | -3,931 | -5,395 | -19,655 | -51,103 | -255,515 | -326,273 | -1,631,365 | -4,241,549 | -21,207,745 |
Here are some more numbers to try:
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