Make use of GCF Calculator to quickly find the Greatest Common Factor of numbers 42, 86 i.e. 2 largest integer by which both the numbers can be divided.

Greatest common factor (GCF) of 42 and 86 is **2**.

GCF(42,86) = 2

*Greatest common factor* or Greatest common divisor (GCD) can be calculated in following way;

- Greatest Common Factor of 42 and 86 by prime factorization method
- Greatest Common Factor of 42 and 86 by matching factors method

**Prime Factorization of 42**

2 | 42 |

3 | 21 |

7 | 7 |

1 |

Prime factors of 42 are 2,3,7. Prime factorization of **42** in exponential form is:

42 = 2^{1}×3^{1}×7^{1}

**Prime Factorization of 86**

2 | 86 |

43 | 43 |

1 |

Prime factors of 86 are 2,43. Prime factorization of **86** in exponential form is:

86 = 2^{1}×43^{1}

∴ So by taking common prime factors GCF of 42 and 86 is 2

**Factors of 42**

List of positive integer factors of 42 that divides 42 without a remainder.

1,2,3,6,7,14,21,42

**Factors of 86**

List of positive integer factors of 86 that divides 86 without a remainder.

1,2,43,86

**Greatest Common Factor**

We found the factors and prime factorization of 42 and 86. The biggest common factor number is the **GCF** number.

So the **greatest common factor 42 and 86** is **2**.

Also check out the Least Common Multiple of 42 and 86

(i) The GCF of 42 and 86 is associative

GCF of 42 and 86 = GCF of 86 and 42

1. What is the GCF of 42 and 86?

Answer: GCF of 42 and 86 is 2.

2. What are the Factors of 42?

Answer: Factors of 42 are 1, 2, 3, 6, 7, 14, 21, 42. There are 8 integers that are factors of 42. The greatest factor of 42 is 42.

3. What are the Factors of 86?

Answer: Factors of 86 are 1, 2, 43, 86. There are 4 integers that are factors of 86. The greatest factor of 86 is 86.

4. How to Find the GCF of 42 and 86?

Answer:

Greatest Common Factor of 42 and 86 = 2

Step 1: Find the prime factorization of 42

42 = 2 x 3 x 7

Step 2: Find the prime factorization of 86

86 = 2 x 43

Step 3: Multiply those factors both numbers have in common in steps i) or ii) above to find the gcf:

GCF = 2

Step 4: Therefore, the greatest common factor of 42 and 86 is 2