GCF for 40 and 820

What is the Greatest common Divisor of 40 and 820?

Answer: GCF of 40 and 820 is 20

(Twenty)

Finding GCF for 40 and 820 using all factors (divisors) listing

The first method to find GCF for numbers 40 and 820 is to list all factors for both numbers and pick the highest common one:

All factors of 40: 1, 2, 4, 5, 8, 10, 20, 40

All factors of 820: 1, 2, 4, 5, 10, 20, 41, 82, 164, 205, 410, 820

So the Greatest Common Factor for 40 and 820 is 20

Finding GCF for 40 and 820 by Prime Factorization

The second method to find GCF for numbers 40 and 820 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 40: 2, 2, 2, 5

All Prime Factors of 820: 2, 2, 5, 41

As we can see there are Prime Factors common to both numbers: 2, 2, 5

Now we need to multiply them to find GCF: 2 × 2 × 5 = 20

GCF Table

Number 1Number 2GCF
258205
268202
278201
288204
298201
3082010
318201
328204
338201
348202
358205
368204
378201
388202
398201
4082020
4182041
428202
438201
448204
458205
468202
478201
488204
498201
5082010
518201
528204
538201
548202

About "Greatest Common Factor" Calculator

This calculator will help you find the greatest common factor (GCF) of two numbers. For example, it can help you find out what is the Greatest common Divisor of 40 and 820? (The answer is: 20). Select the first number (e.g. '40') and the second number (e.g. '820'). After that hit the 'Calculate' button.
Greatest Common Factor (GCF) also known as the Greatest Common Divisor (GCD) or Highest Common Factor (HCF) - it is the largest positive integer that divides each of the integers with zero remainder

FAQ

What is the Greatest common Divisor of 40 and 820?

GCF of 40 and 820 is 20