What is the LCM and GCF of 17 and 21?

The question "What is the LCM and GCF of 17 and 21?" can be split into two questions: "What is the LCM of 17 and 21?" and "What is the GCF of 17 and 21?"

In the question "What is the LCM and GCF of 17 and 21?", LCM is the abbreviation of Least Common Multiple and GCF is the abbreviation of Greatest Common Factor.

To find the LCM, we first list the multiples of 17 and 21 and then we find the smallest multiple they have in common. To find the multiples of any number, you simply multiply the number by 1, then by 2, then by 3 and so on. Here is the beginning list of multiples of 17 and 21:

Multiples of 17: 17, 34, 51, 68, 85, 102, etc.

Multiples of 21: 21, 42, 63, 84, 105, 126, etc.

The least multiple on the two lists that they have in common is the LCM of 17 and 21. Therefore, the LCM of 17 and 21 is 357.

To find the GCF, we first list the factors of 17 and 21 and then we find the largest factor they have in common. The factors of any number, are all the numbers that you can evenly divide into that number.

In other words, the factors of 17 are all the numbers that can evenly divide into 17, and the factors of 21 are all the numbers that can evenly divide into 21. Here are the factors for 17 and 21:

Factors of 17: 1 and 17.

Factors of 21: 1, 3, 7, and 21.

The greatest factor on the two lists that they have in common is the GCF of 17 and 21. Therefore, the GCF of 17 and 21 is 1.

In summary, the answer to the question "What is the LCM and GCF of 17 and 21?" is 357 and 1.

LCM and GCF Calculator
Do you need the LCM and GCF for another set of numbers? No problem, please enter them below:

What is the LCM and GCF of 17 and 22?
Here is the next LCM and GCF question on our list that we have tackled!