Math · 3
When Euler proved the fifth Fermat number was not prime in 1732, into which two factors did he show it split?
Answer
641 and 6,700,417
Euler demonstrated that 2^32+1 (4,294,967,297) factors exactly into the primes 641 and 6,700,417, disproving Fermat's belief that the number was prime.
💡 Did you know?
Pierre de Fermat believed every number of the form 2^(2^n)+1 was prime. He was right for n=0,1,2,3,4 but catastrophically wrong—the fifth one factors into 641×6,700,417.
Other options people guess
- 257 and 16,700,417
- 17 and 252,645,135
- 65537 and 65539
Topics
- fermat-numbers
- euler
- prime-factorization
- history-of-math
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