###### Asked in Factoring and Multiples

Factoring and Multiples

# What is the greatest common factor of 21 and 105?

## Answer

###### Wiki User

###### February 08, 2010 2:58AM

The greatest common factor (GCF) is often also called the
greatest common divisor (GCD) or highest common factor (HCF). Keep
in mind that these different terms all refer to the same thing: the
largest integer which evenly divides two or more numbers.

The greatest common factor of 21 and 105 is 21.

## Related Questions

###### Asked in Factoring and Multiples

### What is the greatest common factor of 63 and 105?

A factor is a divisor - a number that will evenly divide into
another number. The greatest common factor of two or more numbers
is the largest factor that both numbers have in common.
One way to determine the common factors and greatest common
factor is to find all the factors of the numbers and compare
them.
The factors of 63 are 1, 3, 7, 9, 21, and 63.
The factors of 105 are 1, 3, 5, 7, 15, 21, 35, and 105.
The common factors are 1, 3, 7 and 21. Therefore, the greatest
common factor is 21.
The GCF is 21.

###### Asked in Factoring and Multiples

### What is the greatest common factor of 42 and 105?

A factor is a divisor - a number that will evenly divide into
another number. The greatest common factor of two or more numbers
is the largest factor that both numbers have in common.
One way to determine the common factors and greatest common
factor is to find all the factors of the numbers and compare
them.
The factors of 42 are 1, 2, 3, 6, 7, 14, 21, and 42.
The factors of 105 are 1, 3, 5, 7, 15, 21, 35, and 105.
The common factors are 1, 3, 7, and 21. Therefore, the greatest
common factor is 21.
The GCF of 42 and 105 is 21