  We construct spectra of decays of the resonance X(3872) with good analytical
and unitary properties which allows to define the branching ratio of the
X(3872) \to D^{*0}\bar D^0 + c.c. decay studying only one more decay, for
example, the X(3872)\to\pi^+\pi^- J/\psi(1S) decay, and show that our spectra
are effective means of selection of models for the resonance X(3872).
  Then we discuss the scenario where the X(3872 resonance is the c\bar c =
\chi_{c1}(2P) charmonium which "sits on" the D^{*0}\bar D^0 threshold.
  We explain the shift of the mass of the X(3872) resonance with respect to the
prediction of a potential model for the mass of the \chi_{c1}(2P) charmonium by
the contribution of the virtual D^*\bar D+c.c. intermediate states into the
self energy of the X(3872) resonance. This allows us to estimate the coupling
constant of the X(7872) resonance with the D^{*0}\bar D^0 channel, the
branching ratio of the X(3872) \to D^{*0}\bar D^0 + c.c. decay, and the
branching ratio of the X(3872) decay into all non-D^{*0}\bar D^0 + c.c. states.
We predict a significant number of unknown decays of X(3872) via two
gluons:X(3872)\to gluons\ gluon\to hadrons.
