What is the greatest common factor of 198 and 432?
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Detailed Answer: Greatest Common Divisor explained here

You have reached us maybe looking for answers to the questions like: What is the greatest common factor of 198 and 432? or what is the highest common factor (HCF) of 198 and 432?
What is the GCF of 198 and 432?
The first step to find the gcf of 198 and 432 is to list the factors of each number. The factors of 198 are 1, 2, 3, 6, 9, 11, 18, 22, 33, 66, 99 and 198. The factors of 432 are 1, 2, 3, 4, 6, 8, 9, 12, 16, 18, 24, 27, 36, 48, 54, 72, 108, 144, 216 and 432. So, the Greatest Common Factor for these numbers is 18 because it divides all them without a remainder. Read more about Common Factors below.
See also:
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(198,432).
In this case we have:
 The factors of 198 (all the whole numbers that can divide the number without a remainder) are 1, 2, 3, 6, 9, 11, 18, 22, 33, 66, 99 and 198;
 The factors of 432 are 1, 2, 3, 4, 6, 8, 9, 12, 16, 18, 24, 27, 36, 48, 54, 72, 108, 144, 216 and 432.
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 198 and 432 is 18. The GCF is the largest common positive integer that divides all the numbers (198,432) 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