Best Answer

Short answer: There are none.

There is neither a greatest common factor nor common factors of a single number, such as 81, because there cannot be any form of common factor without two or more numbers to compare. Common factors are factors that the numbers being compared have in common. The greatest common factor is the largest factor that all the numbers being compared have in common. Thus, since there are not two or more numbers to compare, there are neither common factors nor a greatest common factor.

The factors of 81 are 1, 3, 9, 27, and 81.

Examples:

The common factors of 18 and 81 are 1, 3, and 9; the greatest common factor is 9.

The common factors of 20 and 81 are only 1; the greatest common factor is 1.

The common factors of 39 and 81 are 1 and 3; the greatest common factor is 3.

The common factors of 81 and 243 are 1, 3, 9, 27, and 81; the greatest common factor is 81.

More answers

The prime factors of 45 are 3, 3 and 5

The prime factors of 81 are 3, 3, 3 and 3.

So two 3s are common to both numbers so 3 x 3 = 9 and that is the greatest common factor of the two.

GCD: 9

LCM: 567

9

Q: What are the greatest common factors of 45 and 81?

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Factors of 45: 1 3 5 9 15 45 Factors of 81: 1 3 927 81 Factors of 63: 1 3 7 9 21 63 The GCF of 45, 81, and 63 is 9

The greatest common factor is 9

The greatest common factor of 81 and 45 is 9Factors of 45: 1 3 5 9 15 45Factors of 81: 1 3 9 27 81The GCF of 45 and 81 is 9It is: 9

The GCF of 81 and 135 is 27.81= 1x81,3x27 135= 1x135, 5x27The factors of 81 are:1, 3, 9, 27, 81The factors of 135 are:1, 3, 5, 9, 15, 27, 45, 135The common factors are:1, 3, 9, 27The Greatest Common Factor:GCF = 27

The factors of 18 are 1, 2, 3, 6, 9, and 18. The factors of 81 are 1, 3, 9, 27, and 81. The common factors are 1, 3, and 9. Therefore, the greatest common factor is 9. You can also determine the greatest common factor from the prime factors. The prime factors of 18 are 2, 3, and 3. The prime factors of 81 are 3, 3, 3, and 3. The prime factors in common are 3 and 3, so the greatest common factor is 3 x 3 = 9.

Related questions

9

The factors of 45 are: 1, 3, 5, 9, 15, 45The factors of 81 are: 1, 3, 9, 27, 81The common factors are: 1, 3, 9The Greatest Common Factor (GCF) is: 9

Factors of 45: 1 3 5 9 15 45 Factors of 81: 1 3 927 81 Factors of 63: 1 3 7 9 21 63 The GCF of 45, 81, and 63 is 9

The factors of 45 are: 1, 3, 5, 9, 15, 45The factors of 81 are: 1, 3, 9, 27, 81The common factors are: 1, 3, 9The Greatest Common Factor (GCF) is: 9

The greatest common factor is 9

The greatest common factor of 81 and 45 is 9Factors of 45: 1 3 5 9 15 45Factors of 81: 1 3 9 27 81The GCF of 45 and 81 is 9It is: 9

GCF (45, 81, 90) = 9

Factors of 81: 1, 3, 9, 27, 81 Factors of 135: 1, 3, 5, 9, 15, 27, 45, 135 GCF (81, 135) = 27

Factors of 81: 1, 3, 9, 27, 81Factors of 135: 1, 3, 5, 9, 15, 27, 45, 135GCF (81, 135) = 27

The GCF of 81 and 135 is 27.81= 1x81,3x27 135= 1x135, 5x27The factors of 81 are:1, 3, 9, 27, 81The factors of 135 are:1, 3, 5, 9, 15, 27, 45, 135The common factors are:1, 3, 9, 27The Greatest Common Factor:GCF = 27

The GCF is 9.

They are 1 and 9