  The skyrmionic mass was calculated in the main order of the gradient
expansion in derivatives of the rotation matrix. The mass is proportinal to the
topological invariant which is the absolut value of the degree of the mapping.
The coefficient is defined by the exchange interaction. The charged skyrmions
in magnetic field give rise to a special branch of cyclotron resonance with the
frequency defined by the exchange interaction and have the corresponding term
in their minimal energy. The possibility of an extra bound electron and neutral
skyrmions is discussed.
