Q: What are the factor combinations of the number 217,987?

 A:
Positive:   1 x 2179877 x 3114111 x 1981719 x 1147377 x 2831133 x 1639149 x 1463209 x 1043
Negative: -1 x -217987-7 x -31141-11 x -19817-19 x -11473-77 x -2831-133 x -1639-149 x -1463-209 x -1043


How do I find the factor combinations of the number 217,987?

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 217,987, 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.

1 217,987
-1 -217,987

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 217,987.

Example:
1 x 217,987 = 217,987
and
-1 x -217,987 = 217,987
Notice both answers equal 217,987

With that explanation out of the way, let's continue. Next, we take the number 217,987 and divide it by 2:

217,987 ÷ 2 = 108,993.5

If the quotient is a whole number, then 2 and 108,993.5 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:

1 217,987
-1 -217,987

Now, we try dividing 217,987 by 3:

217,987 ÷ 3 = 72,662.3333

If the quotient is a whole number, then 3 and 72,662.3333 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:

1 217,987
-1 -217,987

Let's try dividing by 4:

217,987 ÷ 4 = 54,496.75

If the quotient is a whole number, then 4 and 54,496.75 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:

1 217,987
-1 217,987
Keep dividing by the next highest number until you cannot divide anymore.

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

171119771331492091,0431,4631,6392,83111,47319,81731,141217,987
-1-7-11-19-77-133-149-209-1,043-1,463-1,639-2,831-11,473-19,817-31,141-217,987

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