Posted 23 Mar 2013 Perfect numbers are number whose sum of factors are twice the number itself. Example 1. 6 factors of 6 are 1,2,3 and 6 sum=12 i.e 2 * 6 2. 28 factors 1,2,4,7,14,28 sum=56 i.e 2 * 28 can you tell any other perfect no? 0 Share this post Link to post Share on other sites

0 Posted 23 Mar 2013 I am only aware of this general rule. P = 2^{p-1}(2^{p} - 1), where M = 2^{p} - 1 is a Mersenne prime. Example: 2*(2^{2} - 1) = 6 2^{2}*(2^{3} - 1) = 28 2^{4}*(2^{5} - 1) = 496 2^{6}*(2^{7} - 1) = 8128 etc. That is not to say there aren't any other possibilities for finding perfect numbers. 0 Share this post Link to post Share on other sites

0 Posted 23 Mar 2013 (edited) 1 factors 1, 1 sum =2 i.e. 2*1 Edited 23 Mar 2013 by TimeSpaceLightForce 0 Share this post Link to post Share on other sites

0 Posted 23 Mar 2013 1 factors 1, 1 sum =2 i.e. 2*1 1 has only 1 as a factor so sum is 1 0 Share this post Link to post Share on other sites

0 Posted 23 Mar 2013 (edited) Didn`t find one yet Edited 23 Mar 2013 by wolfgang 0 Share this post Link to post Share on other sites

0 Posted 23 Mar 2013 Perfect numbers are number whose sum of factors are twice the number itself. Example 1. 6 factors of 6 are 1,2,3 and 6 sum=12 i.e 2 * 6 2. 28 factors 1,2,4,7,14,28 sum=56 i.e 2 * 28 can you tell any other perfect no? I would rather say they are half perfect because their factors sum is twice of them. 1 is perfect. 0 Share this post Link to post Share on other sites

0 Posted 25 Mar 2013 Perfect numbers are number whose sum of factors are twice the number itself. Example 1. 6 factors of 6 are 1,2,3 and 6 sum=12 i.e 2 * 6 2. 28 factors 1,2,4,7,14,28 sum=56 i.e 2 * 28 can you tell any other perfect no? I would rather say they are half perfect because their factors sum is twice of them. 1 is perfect. In old (Euclid) times, they did not count the number as its own divisor, but they did count 1. Thus, Perfect Number used to be equal to the sum of its divisors (Aliquot Parts.) (Don't quote me on that.) 0 Share this post Link to post Share on other sites

Posted

Perfect numbers are number whose sum of factors are twice the number itself.

Example

1. 6 factors of 6 are 1,2,3 and 6 sum=12 i.e 2 * 6

2. 28 factors 1,2,4,7,14,28 sum=56 i.e 2 * 28

can you tell any other perfect no?

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