Q: What are the factor combinations of the number 21,824?

 A:
Positive:   1 x 218242 x 109124 x 54568 x 272811 x 198416 x 136422 x 99231 x 70432 x 68244 x 49662 x 35264 x 34188 x 248124 x 176
Negative: -1 x -21824-2 x -10912-4 x -5456-8 x -2728-11 x -1984-16 x -1364-22 x -992-31 x -704-32 x -682-44 x -496-62 x -352-64 x -341-88 x -248-124 x -176


How do I find the factor combinations of the number 21,824?

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 21,824, 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 21,824
-1 -21,824

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 21,824.

Example:
1 x 21,824 = 21,824
and
-1 x -21,824 = 21,824
Notice both answers equal 21,824

With that explanation out of the way, let's continue. Next, we take the number 21,824 and divide it by 2:

21,824 ÷ 2 = 10,912

If the quotient is a whole number, then 2 and 10,912 are factors. In this case, the quotient is a whole number. Write them in the table inside the other two factors like the below example. Don't forget to write the negative numbers too!

Here is what our table should look like at this step:

1 2 10,912 21,824
-1 -2 -10,912 -21,824

Now, we try dividing 21,824 by 3:

21,824 ÷ 3 = 7,274.6667

If the quotient is a whole number, then 3 and 7,274.6667 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 2 10,912 21,824
-1 -2 -10,912 -21,824

Let's try dividing by 4:

21,824 ÷ 4 = 5,456

If the quotient is a whole number, then 4 and 5,456 are factors. In this case, the quotient is a whole number. Write them in the table inside the other two factors like the below example. Don't forget to write the negative numbers too!

Here is what our table should look like at this step:

1 2 4 5,456 10,912 21,824
-1 -2 -4 -5,456 -10,912 21,824
Keep dividing by the next highest number until you cannot divide anymore.

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

12481116223132446264881241762483413524966827049921,3641,9842,7285,45610,91221,824
-1-2-4-8-11-16-22-31-32-44-62-64-88-124-176-248-341-352-496-682-704-992-1,364-1,984-2,728-5,456-10,912-21,824

More Examples

Here are some more numbers to try:

Try the factor calculator

Explore more about the number 21,824:


Ask a Question