Genesis 5:31

And all the days of Lamech that passed were seven hundred and seventy-seven years, and then he died. In truth, when Noah was five hundred years old, he conceived Shem, Ham, and Japheth

Other versions

King James Version

And all the days of Lamech were seven hundred seventy and seven years: and he died.

English Standard Version

Thus all the days of Lamech were 777 years, and he died.

New International Version

Altogether, Lamech lived 777 years, and then he died.