Linked from

The 7 pages that link to Perfect number, each with the reason it gives.

• Divisor functionRelated: A perfect number satisfies σ(n)=2n.

• Mersenne primeBroader topic: The formula 2^(p−1)(2^p−1) constructs one whenever 2^p−1 is prime.

• Even numberRelated: Every known even perfect number has a form tied to a Mersenne prime.

• Euclid–Euler theoremNarrower topic: The theorem classifies precisely the perfect numbers that are even.

• Aliquot sequenceBroader topic: Its next term equals itself, producing a fixed-point sequence.

• Aliquot sumBroader topic: A perfect number is a fixed point of the aliquot-sum operation.

• Catalan–Mersenne conjectureRelated: Every even perfect number is associated with a Mersenne prime, a central neighboring topic.