+864 For a positive integer $n$, $\phi(n)$ denotes the number of positive integers less than or equal to $n$ that are relatively prime to $n$.
What is $\phi(25)$?
+67 gcd(25,1)=1 I hope you can count the 1s!
gcd(25,2)=1
gcd(25,3)=1
gcd(25,4)=1
gcd(25,5)=5
gcd(25,6)=1
gcd(25,7)=1
gcd(25,8)=1
gcd(25,9)=1
gcd(25,10)=5
gcd(25,11)=1
gcd(25,12)=1
gcd(25,13)=1
gcd(25,14)=1
gcd(25,15)=5
gcd(25,16)=1
gcd(25,17)=1
gcd(25,18)=1
gcd(25,19)=1
gcd(25,20)=5
gcd(25,21)=1
gcd(25,22)=1
gcd(25,23)=1
gcd(25,24)=1
gcd(25,25)=25
