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Yes. Look at http://en.wikipedia.org/wiki/Euler's_totient_function#Inequalities:
$$\varphi(n)>\frac{n}{e^\gamma\log\log n + \frac{3}{\log\log n}}$$ for $n>2$.
Yes. Look at http://en.wikipedia.org/wiki/Euler's_totient_function#Inequalities
