We obtain model independent relations among neutrino masses and leptogenesis parameters. We find exact relations that involve the CP asymmetries ε_{N_α}, the washout parameters m̃_α and θ_αβ, and the neutrino masses m_i and M_α, as well as powerful inequalities that involve just m̃_α and m_i. We prove that the Yukawa interactions of at least two of the heavy singlet neutrinos are in the strong washout region (m̃_α ≫ 10⁻³ eV).