alleryWhich description fits a perfect number?
AA number equal to the sum of its proper divisors
BA number whose square is equal to itself
CA number that has no proper divisors at all
DA number whose digits are all the same
Answer & Solution
Correct answer: A. A number equal to the sum of its proper divisors
1. Proper divisors are divisors excluding the number itself.
2. A perfect number equals the sum of its positive proper divisors.
3. Example: 1 + 2 + 3 = 6.
_Source: Wikipedia, Perfect number, lead section_
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