  In 1990, Spie\ss \, gave some identities of harmonic numbers including the
types of $\sum_{\ell=1}^n\ell^k H_\ell$, $\sum_{\ell=1}^n\ell^k H_{n-\ell}$ and
$\sum_{\ell=1}^n\ell^k H_\ell H_{n-\ell}$. In this paper, we derive several
formulas of hyperharmonic numbers including $\sum_{\ell=0}^{n} {\ell}^{p}
h_{\ell}^{(r)} h_{n-\ell}^{(s)}$ and $\sum_{\ell=0}^n
\ell^{p}(h_{\ell}^{(r)})^{2}$. Some more formulas of generalized hyperharmonic
numbers are also shown.
