We consider a stationary model of the propagation of galactic cosmic rays (GCR) in the heliosphere and interstellar space adjacent to it. In this case the heliosphere is viewed as two-layer medium consisting of two spherically symmetric solar regions adjacent to each other. In the heliosphere interior bounded by a standing termination shock the solar wind velocity is supersonic and in the heliosphere exterior limited by the heliopause it is subsonic. The scattering of GCR in these regions is characterized by different ways and corresponding diffusion coefficients. In the interstellar medium, the solar wind velocity is assumed to equal zero and the scattering becomes weaker. As this takes place, no particle sources are presumed to exist at the boundaries between the layers. The exact analytical solution of the corresponding mathematical problem presents no fundamental difficulties but it is extremely cumbersome. Analytical expressions for the GCR spectra both for high-energy particles (more than 2500 MeV) and for low-energy particles (less than 1400 MeV) are obtained for each region of their propagation. The distribution of the GCR low-energy particles corresponds to the results obtained by the Voyager spacecraft. It is shown that, regardless of the scattering mode in the inner and outer parts of the heliosphere, the density of low-energy particles increases continuously from the Sun to the heliosphere boundary.