Q: WHAT YEAR WAS MAHALALEEL BORN?
A: IT DEPENDS WHAT CALENDAR YOU ARE USING!
On the Gregorian calendar (the one you might have on your wall) the year was 3651 BC.
On the Hebrew calendar, sometimes called the biblical calendar, the year was 396 AM.
Genesis 5:12 - And Cainan lived seventy years and begat Mahalaleel