The chapter 5 of Genesis reports a list of “antediluvian patriarchs” , with their precise age. Apparently these figures are a nonsense as well this sequence of personages. Any attempt to understand their meaning, apart from simple acceptance of those data typical of orthodox religion, is a sterile exercise of fantasy. The first 11 chapters of Genesis in all evidence are a mythological account, similar to the various mythologies of the same area, each of them reporting their proper list of kings and how long they reigned.
Almost certainly those mythologies, and the first 11 chapters of Genesis with them, have a historical informative content, but it’s impossible to establish it with some degree of reliability, as well impossible is to establish the real meaning of the figures handed down by them.
Following are these figures as reported by the King James version (other versions report different figures)
And Adam lived an hundred and thirty years, and begat a son in his own likeness, and after his image; and called his name Seth:
And the days of Adam after he had begotten Seth were eight hundred years: and he begat sons and daughters:
And all the days that Adam lived were nine hundred and thirty years: and he died.
And Seth lived an hundred and five years, and begat Enos:
And Seth lived after he begat Enos eight hundred and seven years, and begat sons and daughters:
And all the days of Seth were nine hundred and twelve years: and he died.
And Enos lived ninety years, and begat Cainan:
And Enos lived after he begat Cainan eight hundred and fifteen years, and begat sons and daughters:
And all the days of Enos were nine hundred and five years: and he died.
And Cainan lived seventy years and begat Mahalaleel:
And Cainan lived after he begat Mahalaleel eight hundred and forty years, and begat sons and daughters:
And all the days of Cainan were nine hundred and ten years: and he died.
And Mahalaleel lived sixty and five years, and begat Jared:
And Mahalaleel lived after he begat Jared eight hundred and thirty years, and begat sons and daughters:
And all the days of Mahalaleel were eight hundred ninety and five years: and he died.
And Jared lived an hundred sixty and two years, and he begat Enoch:
And Jared lived after he begat Enoch eight hundred years, and begat sons and daughters:
And all the days of Jared were nine hundred sixty and two years: and he died.
And Enoch lived sixty and five years, and begat Methuselah:
And Enoch walked with God after he begat Methuselah three hundred years, and begat sons and daughters:
And all the days of Enoch were three hundred sixty and five years:
And Enoch walked with God: and he was not; for God took him.
And Methuselah lived an hundred eighty and seven years, and begat Lamech.
And Methuselah lived after he begat Lamech seven hundred eighty and two years, and begat sons and daughters:
And all the days of Methuselah were nine hundred sixty and nine years: and he died.
And Lamech lived an hundred eighty and two years, and begat a son:
And he called his name Noah, saying, This same shall comfort us concerning our work and toil of our hands, because of the ground which the LORD hath cursed.
And Lamech lived after he begat Noah five hundred ninety and five years, and begat sons and daughters:
And all the days of Lamech were seven hundred seventy and seven years: and he died.
And Noah was five hundred years old: and Noah begat Shem, Ham, and Japheth.
This sequence covers a total period of 1656 years, from the birth of Adam to the universal flood. It’s interesting to note that Methuselah dies the same year of the deluge, while his son Lamech dies 5 year before. However, what this means is and will forever remain a mystery