Goldbach's Conjecture Math

A little curiosity. A world of numbers.

Explore Goldbach’s conjecture with your free prime-pair calculator, and take your curiosity further with a new Learn tab.

YOUR CALCULATOR STAYS FREE
Find one or up to 20 prime pairs, enter numbers up to 35 digits, keep history, save favorites and share results. No ads or app account required.

30 LESSONS, THREE PATHS
Learn about primes, divisibility, factorization, modular arithmetic, Miller–Rabin, Euclid, twin primes, RSA and mathematical proof. Each lesson includes explanations, a worked example and a quiz with feedback. Lessons 1–5 are free.

A DAILY SPARK
Answer a free daily question, build a streak, bookmark lessons and track your progress. Goldbach Plus adds unlimited practice with instant explanations.

EXPLORE THE LAB
The interactive prime sieve up to 100 is free. Plus adds the Ulam spiral, prime-gap charts, Goldbach pair-count charts, CSV export and a factor explorer. Lab calculations use exact methods within their displayed small ranges.

GOLDBACH PLUS
Monthly and annual auto-renewing subscriptions unlock all 30 lessons, unlimited practice and the complete Lab. Both plans provide the same access. The existing calculator, history, favorites and sharing remain free. Prices and billing periods are shown before purchase. Payment is charged to your Apple Account. Subscriptions renew unless canceled at least 24 hours before the current period ends. Manage or cancel in App Store account settings. Restore active purchases in the app.

PRIVATE BY DESIGN
Lessons and math explorations work offline. Calculations and learning progress stay on this device. Progress does not sync between devices. Apple handles purchases. No tracking or advertising SDKs.

Mathematical experiments do not prove the conjecture. Large-number factors may be probable primes rather than certified primes.

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