  We explore the dynamics of long-range Kitaev chain by varying pairing
interaction exponent, $\alpha$. It is well known that distinctive
characteristics on the nonequilibrium dynamics of a closed quantum system are
closely related to the equilibrium phase transitions. Specifically, the return
probability of the system to its initial state (Loschmidt echo), in the finite
size system, is expected to exhibit very nice periodicity after a sudden quench
to a quantum critical point. Where the periodicity of the revivals scales
inversely with the maximum of the group velocity. We show that, contrary to
expectations, the periodicity of the return probability breaks for a sudden
quench to the non-trivial quantum critical point. Further, We find that, the
periodicity of return probability scales inversely with the group velocity at
the gap closing point for a quench to the trivial critical point of truly
long-range pairing case, $\alpha < 1$. In addition, analyzing the effect of
averaging quenched disorder shows that the revivals in the short range pairing
cases are more robust against disorder than that of the long rang pairing case.
We also study the effect of disorder on the non-analyticities of rate function
of the return probability which introduced as a witness of the dynamical phase
transition. We exhibit that, the non-analyticities in the rate function of
return probability are washed out in the presence of strong disorders.
