HP 40gs - Manual (Page 229)

Computer Algebra System (CAS) 14-47
DIVIS
Gives the divisors of an integer.
Example
Typing:
DIVIS(12)
gives:
12 OR 6 OR 3 OR 4 OR 2 OR 1
Note: DIVIS(0) returns 0 OR 1.
EULER
Returns the Euler index of a whole number. The Euler
index of n is the number of whole numbers less than n that
are prime with n.
Example
Typing:
EULER(21)
gives:
12
Explanation: {2,4,5,7,8,10,11,13,15,16,17,19} is
the set of whole numbers less than 21 and prime with 21.
There are 12 members of the set, so the Euler index is12.
FACTOR Decomposes an integer into its prime factors.
Example
Typing:
FACTOR(90)
gives:
2·3 2 ·5
GCD
Returns the greatest common divisor of two integers.
Example
Typing:
GCD(18, 15)
gives:
3
hp40g+.book Page 47 Friday, December 9, 2005 1:03 AM