# RSA-210 factorization

RSA-210 has been factored

N = 245246644900278211976517663573088018467026787678332759743414451715061600830038587216952208399332071549103626827191679864079776723243005600592035631246561218465817904100131859299619933817012149335034875870551067


in two 105-digit prime numbers. http://www.mersenneforum.org/showpost.php?p=354259

 435958568325940791799951965387214406385470910265220196318705482144524085345275999740244625255428455944579
562545761726884103756277007304447481743876944007510545104946851094548396577479473472146228550799322939273


How did we know RSA-210 was a semiprime?

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In RSA $n = p \times q$, where $p$ and $q$ are picked using two large primes by algorithm, RSA Algotithm. This is known as the Integer Factorization Problem. –  Amzoti Oct 7 '13 at 12:57