Dictionary entry

ἑξήκοντα

G. Abbott-Smith's A Manual Greek Lexicon of the New Testament

ἑξήκοντα, οἱ, αἱ, τά

indecl.,

sixty: Mt 13:8, 23, Mk 4:8, 20, Lk 24:13, I Ti 5:9, Re 11:312:613:18.†