Different kinds of averaging of the wavefunctions/densities of the two-electron atomic systems are investigated. Using the Pekeris-like method [2], the ground state wave functions Ψ of the heliumlike atoms with nucleus charge 1 ≤ Z ≤ 5 are calculated in a few coordinate systems including the hyperspherical coordinates {R, α, θ}. The wave functions Ψ av (R) of the hyperspherical radius R are calculated numerically by averaging Ψ over the hyperspherical angles α and θ. The exact analytic representations for the relative derivatives Ψ av (0)/Ψ av (0) and Ψ av (0)/Ψ av (0) are derived. Analytic approximations very close to the actual Ψ av (R) are obtained. Using actual wave functions Ψ, the one-electron densities ρ(r) are calculated as functions of the electron-nucleus distance r. The relevant derivatives ρ (0)/ρ(0) and ρ (0)/ρ(0) characterizing the behavior of ρ(r) near the nucleus are calculated numerically. Very accurate analytical approximations, representing the actual one-electron density both near the nucleus and far away from it, are derived. All the analytical and numerical results are supplemented with tables and graphs.