HP 39gII, User Manual

Page: 179 / 355

Using mathematical functions 169
isprime
Prime integer test. Returns 1 if the integer a is prime;
otherwise, returns 0.
isprime
( a )
Example:
isprime
(1999) returns 1.
ithprime
Nth prime. For the integer n , returns the nth prime number
less than 10,000.
ithprime
( n )
Example:
ithprime
(5) returns 11.
nextprime
Next prime. Returns the next prime number after the
integer a.
nextprime
( a )
Example:
nextprime
(11) returns 13.
powmod
Power and modulo. For the integers a , n , and p , returns
mod p .
powmod
( a, n, p )
Example:
powmod
(5, 2, 13) returns 12.
prevprime
Previous prime. Returns the previous prime number before
the integer a.
prevprime
( a )
Example:
prevprime
(11) returns 7.
euler
Euler's phi (or totient) function. Takes a positive integer x
and returns the number of positive integers less than or
equal to x that are coprime to x.
euler
( x )
Example:
euler
(6) returns 2.
a
n