perplexus.info :: Just Math : Prime divisors

Prime divisors (Posted on 2005-01-04)

6300846559 is such that 6 is divisible by 2; 63, by 3; 630, by 5; 6300, by 7; and, in general, if you take its first N digits, it will be divisible by the N-th prime.

There is only one other such 10 digit number: can you find it?

See The Solution Submitted by e.g.

Rating: 3.7500 (4 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)

re(2): A further analysis (my oopsies)

| Comment 8 of 13 |

(In reply to re: A further analysis by Charlie)

So I mis-counted the four digit solutions

I missed a branch of my tree diagram for the seven and eight digit solutions.

Posted by Jer on 2005-01-04 19:11:40

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