A:
Positive:
1 x 210700217 x 301000317 x 123941359 x 357119119 x 177059413 x 510171003 x 210073001 x 7021
Negative:
-1 x -21070021-7 x -3010003-17 x -1239413-59 x -357119-119 x -177059-413 x -51017-1003 x -21007-3001 x -7021
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 21,070,021, 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 | 21,070,021 | |
| -1 | -21,070,021 |
When you multiply two negative numbers together, you get a positive number. That means both the positive and negative numbers are factors of 21,070,021.
Example:
1 x 21,070,021 = 21,070,021
and
-1 x -21,070,021 = 21,070,021
Notice both answers equal 21,070,021
With that explanation out of the way, let's continue. Next, we take the number 21,070,021 and divide it by 2:
21,070,021 ÷ 2 = 10,535,010.5
If the quotient is a whole number, then 2 and 10,535,010.5 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 | 21,070,021 | |
| -1 | -21,070,021 |
Now, we try dividing 21,070,021 by 3:
21,070,021 ÷ 3 = 7,023,340.3333
If the quotient is a whole number, then 3 and 7,023,340.3333 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 | 21,070,021 | |
| -1 | -21,070,021 |
Let's try dividing by 4:
21,070,021 ÷ 4 = 5,267,505.25
If the quotient is a whole number, then 4 and 5,267,505.25 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 | 21,070,021 | |
| -1 | 21,070,021 |
If you did it right, you will end up with this table:
| 1 | 7 | 17 | 59 | 119 | 413 | 1,003 | 3,001 | 7,021 | 21,007 | 51,017 | 177,059 | 357,119 | 1,239,413 | 3,010,003 | 21,070,021 |
| -1 | -7 | -17 | -59 | -119 | -413 | -1,003 | -3,001 | -7,021 | -21,007 | -51,017 | -177,059 | -357,119 | -1,239,413 | -3,010,003 | -21,070,021 |
Here are some more numbers to try:
Try the factor calculator