12 345 679 x 9 = 111 111 111
12 345 679 x 18 = 222 222 222
12 345 679 x 27 = 333 333 333
12 345 679 x 36 = 444 444 444
12 345 679 x 45 = 555 555 555
12 345 679 x 54 = 666 666 666
12 345 679 x 63 = 777 777 777
12 345 679 x 72 = 888 888 888
12 345 679 x 81 = 999 999 999

12 345 679 x 999 999 = 12 345 678 987 654 321