Q: What are the factor combinations of the number 642,124,745?

 A:
Positive:   1 x 6421247455 x 128424949
Negative: -1 x -642124745-5 x -128424949


How do I find the factor combinations of the number 642,124,745?

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 642,124,745, 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.

1 642,124,745
-1 -642,124,745

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 642,124,745.

Example:
1 x 642,124,745 = 642,124,745
and
-1 x -642,124,745 = 642,124,745
Notice both answers equal 642,124,745

With that explanation out of the way, let's continue. Next, we take the number 642,124,745 and divide it by 2:

642,124,745 ÷ 2 = 321,062,372.5

If the quotient is a whole number, then 2 and 321,062,372.5 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:

1 642,124,745
-1 -642,124,745

Now, we try dividing 642,124,745 by 3:

642,124,745 ÷ 3 = 214,041,581.6667

If the quotient is a whole number, then 3 and 214,041,581.6667 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:

1 642,124,745
-1 -642,124,745

Let's try dividing by 4:

642,124,745 ÷ 4 = 160,531,186.25

If the quotient is a whole number, then 4 and 160,531,186.25 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:

1 642,124,745
-1 642,124,745
Keep dividing by the next highest number until you cannot divide anymore.

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

15128,424,949642,124,745
-1-5-128,424,949-642,124,745

More Examples

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