Explain SMBC — the wiki for Saturday Morning Breakfast Cereal

The Joke

A man asks God two questions. First: "Hey God, do you care whether there exist any odd numbers that are equal to the sum of their proper divisors?" God answers "No." Then: "And if you had a beard, would you shave it?" God answers "Yes." The caption reads: "Proved: God is not a mathematician."

The first question refers to the unsolved problem in mathematics of whether any odd perfect numbers exist. A perfect number is one that equals the sum of its proper divisors (e.g., 6 = 1 + 2 + 3). All known perfect numbers are even, and whether an odd perfect number exists is one of the oldest open questions in number theory. A mathematician would find this question deeply fascinating, but God is indifferent.

The second question is a reworking of the Barber Paradox: if God shaves all those who do not shave themselves, does God shave Himself? By answering "Yes" so casually, God sidesteps the logical paradox entirely, further proving He is not a mathematician, because a mathematician would immediately recognize the self-referential trap.

The Humor

The comedy comes from the contrast between how a mathematician would react to these questions (with obsessive interest and careful logical concern) and God's blunt, uninterested responses. The idea that the omniscient creator of the universe finds one of mathematics' greatest unsolved problems boring is inherently funny. Additionally, God's casual answer to the beard/shaving question -- which is designed to create a logical paradox -- shows He doesn't think in terms of formal logic at all. The punchline "Proved: God is not a mathematician" is delivered in the dry style of a mathematical proof, adding an extra layer of irony.

References

• Odd perfect numbers: An unsolved problem in number theory dating back to Euclid. No odd perfect number has ever been found, but none has been proven impossible.
• The Barber Paradox / Russell's Paradox: A self-referential logical paradox. The classic version asks: "If a barber shaves all those who do not shave themselves, who shaves the barber?"