$var1 = 0x0000805063008357 ;;
Hexadecimal number > 0xffffffff non-portable at (

$var2 = 0x042426FFFFFFFFFF;;
Hexadecimal number > 0xffffffff non-portable at (

printf "0x%0x\n", $var1 ^ $var2;;
0x424a6af9cff7ca8