  We obtain model independent relations among neutrino masses and leptogenesis
parameters. We find exact relations that involve the CP asymmetries
$\epsilon_{N_\alpha}$, the washout parameters $\tilde m_\alpha$ and
$\theta_{\alpha\beta}$, and the neutrino masses $m_i$ and $M_\alpha$, as well
as powerful inequalities that involve just $\tilde m_\alpha$ and $m_i$. We
prove that the Yukawa interactions of at least two of the heavy singlet
neutrinos are in the strong washout region ($\tilde m_\alpha\gg10^{-3} eV$).
