Q: What are the factor combinations of the number 21,455,315?

 A:
Positive:   1 x 214553155 x 42910637 x 306504535 x 613009
Negative: -1 x -21455315-5 x -4291063-7 x -3065045-35 x -613009


How do I find the factor combinations of the number 21,455,315?

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 21,455,315, 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 21,455,315
-1 -21,455,315

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 21,455,315.

Example:
1 x 21,455,315 = 21,455,315
and
-1 x -21,455,315 = 21,455,315
Notice both answers equal 21,455,315

With that explanation out of the way, let's continue. Next, we take the number 21,455,315 and divide it by 2:

21,455,315 ÷ 2 = 10,727,657.5

If the quotient is a whole number, then 2 and 10,727,657.5 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 21,455,315
-1 -21,455,315

Now, we try dividing 21,455,315 by 3:

21,455,315 ÷ 3 = 7,151,771.6667

If the quotient is a whole number, then 3 and 7,151,771.6667 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 21,455,315
-1 -21,455,315

Let's try dividing by 4:

21,455,315 ÷ 4 = 5,363,828.75

If the quotient is a whole number, then 4 and 5,363,828.75 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 21,455,315
-1 21,455,315
Keep dividing by the next highest number until you cannot divide anymore.

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

15735613,0093,065,0454,291,06321,455,315
-1-5-7-35-613,009-3,065,045-4,291,063-21,455,315

More Examples

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