A positive integer is perfect if it is the sum of all its positive factors except itself. There are two perfect integers less than 30. What are they?
Can you help?
Thank you.
2007-12-24 08:56:27 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
6 and 28
6 = 1 + 2 + 3
28 = 1 + 2 + 4 + 7 + 14
Each number is the sum of the positive integers (excluding the number itself) that divide into it without a remainder.
The following web site lists the first 8 perfect numbers:
http://mathworld.wolfram.com/PerfectNumber.html
2007-12-24 09:00:49 · answer #1 · answered by Dr Bob 6 · 3⤊ 0⤋
They are 6 and 28. If you want to generate all even perfect numbers, choose prime p such that 2^p - 1 is a Mersenne prime. Then 2^(p-1)(2^p - 1) is a perfect number. The perfect numbers 6 and 28 correspond to the primes p=2 and p=3, respectively.
2007-12-24 17:30:56 · answer #2 · answered by Anonymous · 2⤊ 0⤋
6 and 28.
6 = 1 + 2 + 3
and
28 = 1 + 2 + 4 + 7 + 14.
2007-12-24 18:59:28 · answer #3 · answered by steiner1745 7 · 1⤊ 0⤋
4 = 2*2 , 2+2 = 4
2007-12-24 17:19:10 · answer #4 · answered by Nur S 4 · 0⤊ 4⤋
one is 6
the other is 28
2007-12-24 17:04:59 · answer #5 · answered by βΣΩΩγ 6 · 1⤊ 1⤋