φ is Euler's function. calculate φ(2009)

Ok. I have no examples with this kind of assignments, so I have no idea how to solve this assignment. Could anyone there can navigate me? Tnx

2009 = 7*7*41
phi(2009) = phi(7^2)*phi(41)
if p is a prime, phi(p^k) = p^k- p^(k-1)

So phi(41) = 41-1 =40
and phi(7^2) = 7^2 - 7 = 49 - 7 = 42
And the answer is 40*42.

See Wikipedia http://en.wikipedia.org/wiki/Euler's_tot…

Well, the golden ratio is φ = 1 + (√1 + 5)/2

Therefore... φ = 1.6180339887...

So the answer is 1.6180339887 * 2009 = 3250.6302832983...

I hope this helped.