On Nannacus (who lived to be more than 300 years old) see already nu 24, again tau 71, and generally Zenobius 6.10. Also, apparently, called Annacus (by Stephanus of Byzantium s.v. Ikonion, though Meineke questioned the transmitted text there).
[1] As Karl Scherling notes in his article in Pauly ('Nannakos'), there is a clear similarity between Nannacus and the biblical figure of Enoch (as there is between Deucalion and the biblical figure of Noah).
[2] Zenobius says that Nannacus, anticipating Deucalion's flood, gathered his subjects into a temple and prayed for deliverance. For this see further under tau 71, Ta Nannakou klausomai.