What is the greatest common factor of 26 and 42?
Greatest Common Factor Calculator / Converter
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Detailed Answer:Greatest Common Divisor explained here

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What is the GCF of 26 and 42?
The first step to find the gcf of 26 and 42 is to list the factors of each number. The factors of 26 are 1, 2, 13 and 26. The factors of 42 are 1, 2, 3, 6, 7, 14, 21 and 42. So, the Greatest Common Factor for these numbers is 2 because it divides all them without a remainder. Read more about Common Factors below.
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How to find the Greatest Common Factor
GCF example:
The first step is to find all divisors of each number. For instance, let us find the gcf(26, 42).
In this case we have:
 The factors of 26 (all the whole numbers that can divide the number without a remainder) are 1, 2, 13 and 26;
 The factors of 42 are 1, 2, 3, 6, 7, 14, 21 and 42.
The second step is to analyze which are the common divisors. It is not difficult to see that the 'Greatest Common Factor' or 'Divisor' for 26 and 42 is 2. The GCF is the largest common positive integer that divides all the numbers (26, 42) without a remainder.
The GCF is also known as:
 Greatest common divisor (gcd);
 Highest common factor (hcf);
 Greatest common measure (gcm), or
 Highest common divisor