# Thread: Find the highest power of 3 which divides N.

1. ## Find the highest power of 3 which divides N.

The integers from 200 down to 1 are written consecutively to form the large number N = 200199198197...131211...654321. Find the highest power of 3 which divides N.

2. A quite modest 3^1

3. Can you please explain your reasoning behind this answer?

4. Probably one way to solve this problem is to keep in mind that 9 divides $N$ if and only if the sum of its digits is divisible by 9.

Can you find a way to sum up the digits of this number to use this test?

5. Originally Posted by chris520
Can you please explain your reasoning behind this answer?
Wrote program.
Sum digits = 1902; divisible by 3, not by 9.