GCF for 30 and 645

What is the Greatest common Divisor of 30 and 645?

Answer: GCF of 30 and 645 is 15

(Fifteen)

Finding GCF for 30 and 645 using all factors (divisors) listing

The first method to find GCF for numbers 30 and 645 is to list all factors for both numbers and pick the highest common one:

All factors of 30: 1, 2, 3, 5, 6, 10, 15, 30

All factors of 645: 1, 3, 5, 15, 43, 129, 215, 645

So the Greatest Common Factor for 30 and 645 is 15

Finding GCF for 30 and 645 by Prime Factorization

The second method to find GCF for numbers 30 and 645 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 30: 2, 3, 5

All Prime Factors of 645: 3, 5, 43

As we can see there are Prime Factors common to both numbers: 3, 5

Now we need to multiply them to find GCF: 3 × 5 = 15

GCF Table

Number 1Number 2GCF
1564515
166451
176451
186453
196451
206455
216453
226451
236451
246453
256455
266451
276453
286451
296451
3064515
316451
326451
336453
346451
356455
366453
376451
386451
396453
406455
416451
426453
4364543
446451

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 30 and 645? (The answer is: 15). Select the first number (e.g. '30') and the second number (e.g. '645'). 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 30 and 645?

GCF of 30 and 645 is 15