GCF for 40 and 840

What is the Greatest common Divisor of 40 and 840?

Answer: GCF of 40 and 840 is 40

(Forty)

Finding GCF for 40 and 840 using all factors (divisors) listing

The first method to find GCF for numbers 40 and 840 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 840: 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 15, 20, 21, 24, 28, 30, 35, 40, 42, 56, 60, 70, 84, 105, 120, 140, 168, 210, 280, 420, 840

So the Greatest Common Factor for 40 and 840 is 40

Finding GCF for 40 and 840 by Prime Factorization

The second method to find GCF for numbers 40 and 840 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 840: 2, 2, 2, 3, 5, 7

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

Now we need to multiply them to find GCF: 2 × 2 × 2 × 5 = 40

GCF Table

Number 1Number 2GCF
258405
268402
278403
2884028
298401
3084030
318401
328408
338403
348402
3584035
3684012
378401
388402
398403
4084040
418401
4284042
438401
448404
4584015
468402
478401
4884024
498407
5084010
518403
528404
538401
548406

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 840? (The answer is: 40). Select the first number (e.g. '40') and the second number (e.g. '840'). 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 840?

GCF of 40 and 840 is 40