Q: What are the factor combinations of the number 31,915?

 A:
Positive:   1 x 319155 x 638313 x 245565 x 491
Negative: -1 x -31915-5 x -6383-13 x -2455-65 x -491


How do I find the factor combinations of the number 31,915?

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 31,915, 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 31,915
-1 -31,915

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 31,915.

Example:
1 x 31,915 = 31,915
and
-1 x -31,915 = 31,915
Notice both answers equal 31,915

With that explanation out of the way, let's continue. Next, we take the number 31,915 and divide it by 2:

31,915 ÷ 2 = 15,957.5

If the quotient is a whole number, then 2 and 15,957.5 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 31,915
-1 -31,915

Now, we try dividing 31,915 by 3:

31,915 ÷ 3 = 10,638.3333

If the quotient is a whole number, then 3 and 10,638.3333 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 31,915
-1 -31,915

Let's try dividing by 4:

31,915 ÷ 4 = 7,978.75

If the quotient is a whole number, then 4 and 7,978.75 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 31,915
-1 31,915
Keep dividing by the next highest number until you cannot divide anymore.

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

1513654912,4556,38331,915
-1-5-13-65-491-2,455-6,383-31,915

More Examples

Here are some more numbers to try:

Try the factor calculator

Explore more about the number 31,915:


Ask a Question