A:
Positive:
1 x 218581517 x 312259319 x 1150429133 x 164347149 x 1466991043 x 209571103 x 198172831 x 7721
Negative:
-1 x -21858151-7 x -3122593-19 x -1150429-133 x -164347-149 x -146699-1043 x -20957-1103 x -19817-2831 x -7721
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 21,858,151, 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 | 21,858,151 | |
| -1 | -21,858,151 |
When you multiply two negative numbers together, you get a positive number. That means both the positive and negative numbers are factors of 21,858,151.
Example:
1 x 21,858,151 = 21,858,151
and
-1 x -21,858,151 = 21,858,151
Notice both answers equal 21,858,151
With that explanation out of the way, let's continue. Next, we take the number 21,858,151 and divide it by 2:
21,858,151 ÷ 2 = 10,929,075.5
If the quotient is a whole number, then 2 and 10,929,075.5 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 | 21,858,151 | |
| -1 | -21,858,151 |
Now, we try dividing 21,858,151 by 3:
21,858,151 ÷ 3 = 7,286,050.3333
If the quotient is a whole number, then 3 and 7,286,050.3333 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 | 21,858,151 | |
| -1 | -21,858,151 |
Let's try dividing by 4:
21,858,151 ÷ 4 = 5,464,537.75
If the quotient is a whole number, then 4 and 5,464,537.75 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 | 21,858,151 | |
| -1 | 21,858,151 |
If you did it right, you will end up with this table:
| 1 | 7 | 19 | 133 | 149 | 1,043 | 1,103 | 2,831 | 7,721 | 19,817 | 20,957 | 146,699 | 164,347 | 1,150,429 | 3,122,593 | 21,858,151 |
| -1 | -7 | -19 | -133 | -149 | -1,043 | -1,103 | -2,831 | -7,721 | -19,817 | -20,957 | -146,699 | -164,347 | -1,150,429 | -3,122,593 | -21,858,151 |
Here are some more numbers to try:
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