Q: What are the factor combinations of the number 21,428,987?
A:
Positive:
1 x 2142898779 x 271253
Negative:
-1 x -21428987-79 x -271253
A:
Positive:
1 x 2142898779 x 271253
Negative:
-1 x -21428987-79 x -271253
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 21,428,987, 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 | 21,428,987 | |
-1 | -21,428,987 |
When you multiply two negative numbers together, you get a positive number. That means both the positive and negative numbers are factors of 21,428,987.
Example:
1 x 21,428,987 = 21,428,987
and
-1 x -21,428,987 = 21,428,987
Notice both answers equal 21,428,987
With that explanation out of the way, let's continue. Next, we take the number 21,428,987 and divide it by 2:
21,428,987 ÷ 2 = 10,714,493.5
If the quotient is a whole number, then 2 and 10,714,493.5 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 | 21,428,987 | |
-1 | -21,428,987 |
Now, we try dividing 21,428,987 by 3:
21,428,987 ÷ 3 = 7,142,995.6667
If the quotient is a whole number, then 3 and 7,142,995.6667 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 | 21,428,987 | |
-1 | -21,428,987 |
Let's try dividing by 4:
21,428,987 ÷ 4 = 5,357,246.75
If the quotient is a whole number, then 4 and 5,357,246.75 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 | 21,428,987 | |
-1 | 21,428,987 |
If you did it right, you will end up with this table:
1 | 79 | 271,253 | 21,428,987 |
-1 | -79 | -271,253 | -21,428,987 |
Here are some more numbers to try:
Try the factor calculator