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 A Composite Determination Problem (Posted on 2006-04-23)
Determine whether or not N is a composite number, where

N = 675*2621 + 677*2610 - 1

NOTE:
A prime number (or a prime) is a natural number that has exactly two (distinct) natural number divisors, which are 1 and the prime number itself. A composite number is a positive integer which has a positive divisor other than one or itself. By definition, every integer greater than one is either a prime number or a composite number. The numbers 0 and 1 are considered to be neither prime nor composite.

 See The Solution Submitted by K Sengupta Rating: 4.3333 (3 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
 re: A first stab at the solution | Comment 6 of 14 |
(In reply to A first stab at the solution by e.g.)

From this we can see the last digit is a 1, since all powers of numbers ending in a 6 end in 6 and 6-6+6+6-1=11

I also tried writing this number in base 26:

25 25 25 0 0 0 0 0 0 0 0 1 0 25 25 25 25 25 25 25 25 25 25 25

Which doesn't seem helpful but I thought I'd share.

 Posted by Jer on 2006-04-23 13:21:48

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