Q: What are the factors or divisors of the number 45?

 A: 13591545

How do I find the factors or divisors of the number 45?

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 factors of larger numbers. To find the factors of the number 45, it is easiest to start from the outside in. Here's what we mean:

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.

1 45

Next, we take the number 45 and divide it by 2.

In this case, 45 ÷ 2 = 22.5

If the quotient is a whole number, then 2 and 22.5 are factors. Write them in the table below. If the quotient is not a whole number, skip to the next test.

1 45

Now, we try dividing 45 by 3.

45 ÷ 3 = 15

If the quotient is a whole number, then 3 and 15 are factors. Write them in the table below. If the quotient is not a whole number, skip to the next test.

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

1 3 15 45

Let's try dividing by 4.

45 ÷ 4 = 11.25

If the quotient is a whole number, then 4 and 11.25 are factors. Write them in the table below. If the quotient is not a whole number, skip to the next test.

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

1 3 15 45

We keep dividing by the next largest number, in this case the number 5. If the quotient of 45 ÷ 5 is a whole number, then 5 and your quotient are factors of the number.


Keep dividing by the next highest number until you cannot divide anymore.


What you will end up with is this table:

13591545

All of the numbers in the table above can be evenly divided into the number 45.

Finally, for your reference, here are all of the divisor combinations of the number 45:

1 x 45
3 x 15
5 x 9


More Examples

Here are some more numbers to try:

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