Tags: #open/conjectures #higher-algebra/K-theory  


Kummer showed that if a prime $p$ does not divide the class number $h$, then [Fermat's Last Theorem](Fermat's%20Last%20Theorem.md)holds for exponent $p$.

The Kummer-Vandiver conjecture states that $p$ does not divide the second factor $h_2$. Kummer showed that if $p$ divides the second factor, then $p$ also divides the first factor.