Q: What are the factor combinations of the number 21,537,125?

 A:
Positive:   1 x 215371255 x 430742525 x 861485125 x 172297
Negative: -1 x -21537125-5 x -4307425-25 x -861485-125 x -172297


How do I find the factor combinations of the number 21,537,125?

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 21,537,125, 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 21,537,125
-1 -21,537,125

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 21,537,125.

Example:
1 x 21,537,125 = 21,537,125
and
-1 x -21,537,125 = 21,537,125
Notice both answers equal 21,537,125

With that explanation out of the way, let's continue. Next, we take the number 21,537,125 and divide it by 2:

21,537,125 ÷ 2 = 10,768,562.5

If the quotient is a whole number, then 2 and 10,768,562.5 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 21,537,125
-1 -21,537,125

Now, we try dividing 21,537,125 by 3:

21,537,125 ÷ 3 = 7,179,041.6667

If the quotient is a whole number, then 3 and 7,179,041.6667 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 21,537,125
-1 -21,537,125

Let's try dividing by 4:

21,537,125 ÷ 4 = 5,384,281.25

If the quotient is a whole number, then 4 and 5,384,281.25 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 21,537,125
-1 21,537,125
Keep dividing by the next highest number until you cannot divide anymore.

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

1525125172,297861,4854,307,42521,537,125
-1-5-25-125-172,297-861,485-4,307,425-21,537,125

More Examples

Here are some more numbers to try:

Try the factor calculator

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