In
number theory, two
integers a and
b are said to be
relatively prime,
mutually prime, or
coprime (also spelled
co-prime) if the only positive integer that evenly divides both of them is 1. That is, the only common positive factor of the two numbers is 1. This is equivalent to their
greatest common divisor being 1. The numerator and denominator of a
reduced fraction are coprime. In addition to
and
the notation is sometimes used to indicate that
a and
b are relatively prime.