Q: What are the factor combinations of the number 13,387,891?

 A:
Positive:   1 x 1338789111 x 121708117 x 787523187 x 71593
Negative: -1 x -13387891-11 x -1217081-17 x -787523-187 x -71593


How do I find the factor combinations of the number 13,387,891?

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 13,387,891, it is easier to work with a table - it's called factoring from the outside in.

Outside in Factoring

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 13,387,891
-1 -13,387,891

Why are the negative numbers included?

When you multiply two negative numbers together, you get a positive number. That means both the positive and negative numbers are factors of 13,387,891.

Example:
1 x 13,387,891 = 13,387,891
and
-1 x -13,387,891 = 13,387,891
Notice both answers equal 13,387,891

With that explanation out of the way, let's continue. Next, we take the number 13,387,891 and divide it by 2:

13,387,891 ÷ 2 = 6,693,945.5

If the quotient is a whole number, then 2 and 6,693,945.5 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 13,387,891
-1 -13,387,891

Now, we try dividing 13,387,891 by 3:

13,387,891 ÷ 3 = 4,462,630.3333

If the quotient is a whole number, then 3 and 4,462,630.3333 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 13,387,891
-1 -13,387,891

Let's try dividing by 4:

13,387,891 ÷ 4 = 3,346,972.75

If the quotient is a whole number, then 4 and 3,346,972.75 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 13,387,891
-1 13,387,891
Keep dividing by the next highest number until you cannot divide anymore.

If you did it right, you will end up with this table:

1111718771,593787,5231,217,08113,387,891
-1-11-17-187-71,593-787,523-1,217,081-13,387,891

More Examples

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