# Perfect Numbers

1. Dec 3, 2009

### nomather1471

Show that ----> if n is even perfect number than n $$\equiv$$6(mod10) or n$$\equiv$$8(mod10)

2. Dec 3, 2009

### CRGreathouse

Do you know the Euclid-Euler form?

3. Dec 3, 2009

### nomather1471

2^(p-1) *(2^p-1) formula i think you have said, i know this formula but i haven't get the result with this.

Last edited: Dec 4, 2009
4. Dec 4, 2009

### nomather1471

I can't believe to myself i think i proved :)

Last edited by a moderator: May 4, 2017
5. Dec 6, 2009

### icystrike

yea. it should be it

Last edited by a moderator: May 4, 2017
6. Dec 10, 2009

### nomather1471

it is important point of exponential of 4 is congruence 4 or 6 mod 10, i have missed it i think :)