At least they were alive at the same time. The year numbering system assumes Adam was “born” in year 0. See previous table for calculatng the years from Adam through Noah. From Genesis:
|1946||Abram||100||175||2121||Genesis 21:5 ; 25:7|
|2046||Isaac||60||180||2226||Genesis 25:26 ; 35:28|
There’s a traditional belief in Judaism that Melchisedec, to whom Abraham paid tithes, was Shem. Ever since I heard that I wanted to do the math and see if that was possible.