Schatunowsky's Theorem/Mistake

Source Work

 * The Dictionary
 * $30$
 * $30$

Mistake

 * $30$ is the greatest number such that all the numbers less than it and prime to it are themselves primes. The other numbers with this property are $2$, $3$, $4$, $6$, $8$, $12$, $18$ and $24$.

While all integers are coprime to $1$ (and $30$ in particular), remember that $1$ is not classified as a prime number.

The canonical exposition of this result is for $1$ to be specifically mentioned.