Q: What are the factor combinations of the number 128,765?

 A:
Positive:   1 x 1287655 x 257537 x 1839513 x 990535 x 367965 x 198191 x 1415283 x 455
Negative: -1 x -128765-5 x -25753-7 x -18395-13 x -9905-35 x -3679-65 x -1981-91 x -1415-283 x -455


How do I find the factor combinations of the number 128,765?

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 128,765, 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.

1 128,765
-1 -128,765

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 128,765.

Example:
1 x 128,765 = 128,765
and
-1 x -128,765 = 128,765
Notice both answers equal 128,765

With that explanation out of the way, let's continue. Next, we take the number 128,765 and divide it by 2:

128,765 ÷ 2 = 64,382.5

If the quotient is a whole number, then 2 and 64,382.5 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:

1 128,765
-1 -128,765

Now, we try dividing 128,765 by 3:

128,765 ÷ 3 = 42,921.6667

If the quotient is a whole number, then 3 and 42,921.6667 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:

1 128,765
-1 -128,765

Let's try dividing by 4:

128,765 ÷ 4 = 32,191.25

If the quotient is a whole number, then 4 and 32,191.25 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:

1 128,765
-1 128,765
Keep dividing by the next highest number until you cannot divide anymore.

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

157133565912834551,4151,9813,6799,90518,39525,753128,765
-1-5-7-13-35-65-91-283-455-1,415-1,981-3,679-9,905-18,395-25,753-128,765

More Examples

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