15,241,578,750,190,521
Yes, 123456789 is a multiple of 9
Any multiple of 2520.
123456789 + 123456789 = 246913578
Yes, 123456789 is a multiple of 3. To find out if it's a multiple of 3, you add the digits. In this case you would add 1+2+3+4+5+6+7+8+9=45. Now you take that 45 and divide by 3. If there is no remainder it is a multiple but if there is a remainder it is not a multiple. So in this case 45/3=15 with no remainder.
the answer is 15241578750190521
you get cheese
543234567890-123456789 = 543111111101
1
324536
123456789 + 36853168 = 160309957
123456789 +987654321 =1111111110
123456789 X 123456789 is1.52415788 × 1016