Euler used trial division , improving on Pietro Cataldi 's method , so that at most 372 divisions were needed .
The primality of this number was proven by Leonhard Euler , who reported the proof in a letter to Daniel Bernoulli written in 1772 .
Leonhard Euler used trial division , improving on Pietro Cataldi 's method , so that at most 372 divisions were needed .
The primality of this number was proven by Leonhard Euler , who reported the proof in a letter to Daniel Bernoulli written in 1772 .