Q: What are the factor combinations of the number 61?

 A:
Positive:   1 x 61
Negative: -1 x -61


How do I find the factor combinations of the number 61?

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 61, 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 61
-1 -61

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 61.

Example:
1 x 61 = 61
and
-1 x -61 = 61
Notice both answers equal 61

With that explanation out of the way, let's continue. Next, we take the number 61 and divide it by 2:

61 ÷ 2 = 30.5

If the quotient is a whole number, then 2 and 30.5 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 61
-1 -61

Now, we try dividing 61 by 3:

61 ÷ 3 = 20.3333

If the quotient is a whole number, then 3 and 20.3333 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 61
-1 -61

Let's try dividing by 4:

61 ÷ 4 = 15.25

If the quotient is a whole number, then 4 and 15.25 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 61
-1 61
Keep dividing by the next highest number until you cannot divide anymore.

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

161
-1-61

More Examples

Here are some more numbers to try:

Try the factor calculator

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