All open problems
Source labels openChecked July 26, 2026

WikipediaNumber theory

Perfect numbers

Odd Perfect Number Conjecture.* The Odd Perfect Number Conjecture states that all perfect numbers are even. Reference:* Wikipedia

Mathematical statement

Odd Perfect Number Conjecture.* The Odd Perfect Number Conjecture states that all perfect numbers are even. Reference:* Wikipedia

Statement source: Wikipedia statement material

Statement terms: CC-BY-SA-4.0

Attributed source material. Reuse must follow the linked attribution and share-alike terms.

Statement artifacts, not proofs

These records expose exact Lean propositions and statement-only wrappers. Defining a proposition does not supply a proof of it. A placeholder-bearing target also contains no proof. Elaboration checks syntax and types; it does not certify that a formalization perfectly captures every nuance of the informal problem.

Pinned Lean formulation 1

odd_perfect_number_conjecture

Canonical source
Complete statement target, proof intentionally absentLean 4
theorem odd_perfect_number_conjecture (n : ) (hn : Perfect n) : Even n := by  sorry
Statement source
Formal Conjectures
Lean version
v4.27.0
Placeholder
Present; no proof artifact
Source evidence
Pinned source index
Fidelity review
Community formulation

References