A:
Positive:
1 x 210184155 x 420368311 x 191076555 x 382153401 x 52415953 x 220552005 x 104834411 x 4765
Negative:
-1 x -21018415-5 x -4203683-11 x -1910765-55 x -382153-401 x -52415-953 x -22055-2005 x -10483-4411 x -4765
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 21,018,415, 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 | 21,018,415 | |
| -1 | -21,018,415 |
When you multiply two negative numbers together, you get a positive number. That means both the positive and negative numbers are factors of 21,018,415.
Example:
1 x 21,018,415 = 21,018,415
and
-1 x -21,018,415 = 21,018,415
Notice both answers equal 21,018,415
With that explanation out of the way, let's continue. Next, we take the number 21,018,415 and divide it by 2:
21,018,415 ÷ 2 = 10,509,207.5
If the quotient is a whole number, then 2 and 10,509,207.5 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 | 21,018,415 | |
| -1 | -21,018,415 |
Now, we try dividing 21,018,415 by 3:
21,018,415 ÷ 3 = 7,006,138.3333
If the quotient is a whole number, then 3 and 7,006,138.3333 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 | 21,018,415 | |
| -1 | -21,018,415 |
Let's try dividing by 4:
21,018,415 ÷ 4 = 5,254,603.75
If the quotient is a whole number, then 4 and 5,254,603.75 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 | 21,018,415 | |
| -1 | 21,018,415 |
If you did it right, you will end up with this table:
| 1 | 5 | 11 | 55 | 401 | 953 | 2,005 | 4,411 | 4,765 | 10,483 | 22,055 | 52,415 | 382,153 | 1,910,765 | 4,203,683 | 21,018,415 |
| -1 | -5 | -11 | -55 | -401 | -953 | -2,005 | -4,411 | -4,765 | -10,483 | -22,055 | -52,415 | -382,153 | -1,910,765 | -4,203,683 | -21,018,415 |
Here are some more numbers to try:
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