Q: What are the factor combinations of the number 28,105?

 A:
Positive:   1 x 281055 x 56217 x 401511 x 255535 x 80355 x 51173 x 38577 x 365
Negative: -1 x -28105-5 x -5621-7 x -4015-11 x -2555-35 x -803-55 x -511-73 x -385-77 x -365


How do I find the factor combinations of the number 28,105?

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 28,105, 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 28,105
-1 -28,105

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 28,105.

Example:
1 x 28,105 = 28,105
and
-1 x -28,105 = 28,105
Notice both answers equal 28,105

With that explanation out of the way, let's continue. Next, we take the number 28,105 and divide it by 2:

28,105 ÷ 2 = 14,052.5

If the quotient is a whole number, then 2 and 14,052.5 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 28,105
-1 -28,105

Now, we try dividing 28,105 by 3:

28,105 ÷ 3 = 9,368.3333

If the quotient is a whole number, then 3 and 9,368.3333 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 28,105
-1 -28,105

Let's try dividing by 4:

28,105 ÷ 4 = 7,026.25

If the quotient is a whole number, then 4 and 7,026.25 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 28,105
-1 28,105
Keep dividing by the next highest number until you cannot divide anymore.

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

15711355573773653855118032,5554,0155,62128,105
-1-5-7-11-35-55-73-77-365-385-511-803-2,555-4,015-5,621-28,105

More Examples

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