The last digit has to be 0.

Since any whole number multiplied by, say, 10, equals zero.

And I think... the 19th may also be...

10,20,30,40,50,60,70,80,90,100 add in a zero, as do 5*2,12*15,22*25,32*35,42*45,52*55,62*65, 72*75, 82*85, & 92*95.

Aye, there's 20 of them. So the 19th place from the right is also a 0.