We can now test to see if this is a prime number by using the
ISPRIME?
function from the
MATH
menu. This is found in the Integer section of the
CAS function list as shown right.
It returns a value of
0
(false) indicating that it is not a prime number.
Using the
FACTOR
function from the
menu shows that its factors
are 641 and 6700417.
Note: The
ISPRIME?
function gives correct results for integers up to
14
10 . Beyond that level the results are highly probable to be
correct but not guaranteed. They are obtained using “Rabin’s
Algorithm” and are called ‘pseudo primes’.
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