Last digit of 19=(9)*2=18,Hence 19*18=342

Last digit of 342=(2)*2=4,Hence 342*4=1368

Last digit of 1368=(8)*2=16,Hence 1368*16=21888

Last digit of 21888=(8)*2=16,Hence 21888*16=350208

Last digit of 350208=(8)*2=16,Hence 350208*16=5603328

so ans is 5603328