SB 9.17.7
sastim varsa-sahasrani
sastim varsa-satani ca
nalarkad aparo rajan
bubhuje medinim yuva
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Alarka, the son of Dyuman, reigned over the earth for sixty-six thousand years, my dear King Pariksit. No one other than him has reigned over the earth for so long as a young man.