  In the following text we show set--theoretical entropy of Euler's totient
function and contravariant set--theoretical entropy of Dedekind psi function
are zero. Also contravariant set--theoretical entropy of Euler's totient
function and set--theoretical entropy of Dedekind psi function are $+\infty$.
We pay attention to some of the other number theoretical special functions too.
We continue our studies on Alexandroff topologies induced by Euler's totient
function and Dedekind psi function.
