There cannot be a greatest common factor (GCF) of just one number. To be common there need to be at least two numbers. If you find all the factors of two or more numbers, and you find some factors are the same ("common"), then the largest of those common factors is the Greatest Common Factor.
Prime factorization of 27 = 3x3x3 Prime factorization of 49 = 7x7 From the prime factorizations it is clear that gcf is 1.
Prime factorization for 135 = 3 x 3 x 3 x 5Prime factorization for 351 = 3 x 3 x 3 x 13GCF of (135,351) = 27
The GCF of 9, 18, 27, and 36 is 9. The prime factorization of 9 is 3*3 The prime factorization of 18 is 2*3*3 The prime factorization of 27 is 3*3*3 The prime factorization of 36 is 2*2*3*3 The GCF is 3*3 = 9
The GCF of 18, 25, and 27 is 1. The prime factorization of 18 is 2*3*3 The prime factorization of 25 is 5*5 The prime factorization of 27 is 3*3*3 Since they have no factors in common, their GCF is 1, and they are called "coprime."
The GCF of 18, 27, and 63 is 9. The prime factorization of 18 is 2*3*3 The prime factorization of 27 is 3*3*3 The prime factorization of 63 is 3*3*7 The GCF is 3*3 = 9.
The GCF of 18, 27, and 99 is 9. The prime factorization of 18 is 2*3*3. The prime factorization of 27 is 3*3*3 The prime factorization of 99 is 3*3*11 So the GCF = 3*3 = 9.
The GCF of 27 and 39 is 3. The prime factorization of 27 is 3*3*3 The prime factorization of 39 is 3*13 So the GCF of 27 and 39 is 3.
The GCF of 16, 18 and 27 is 1. The prime factorization of 16 is 2*2*2*2 The prime factorization of 18 is 2*3*3 The prime factorization of 27 is 3*3*3 The numbers have no common factors except 1, so that is their GCF.
The greatest common factor of 18, 27, 36, and 48 is 3. The prime factorization of 18 is 2*3*3 The prime factorization of 27 is 3*3*3 The prime factorization of 36 is 2*2*3*3 The prime factorization of 48 is 2*2*2*2*3 The common factors are 1 and 3, and the GCF is 3.
Prime factorization of 297891 = 33 x 11 x 17 x 59 Prime factorization of 2187 = 37 gcd(297891, 2187) = 33 = 27.
The prime factorization in exponent form of 27 is: 33 = 27
The greatest common factor of 18, 27, and 36 is 9 The prime factorization of 18 is 2*3*3 The prime factorization of 27 is 3*3*3 The prime factorization of 36 is 2*2*3*3 The GCF is 3*3 = 9.