וַיִּֽהְיוּ֙ כָּל־יְמֵי־שֵׁ֔ת שְׁתֵּ֤ים עֶשְׂרֵה֙ שָׁנָ֔ה וּתְשַׁ֥ע מֵא֖וֹת שָׁנָ֑ה וַיָּמֹֽת׃ (ס)
And all the days of Seth were nine hundred and twelve years; and he died.
Read Kabbalistic (mystical) interpretations of Genesis 5:8: Zohar and classical Jewish mystical sources, free online.