Define

where

(Davenport 1980, p. 121), is the Mangoldt function, and is the totient function. Now define

where the sum is over relatively prime to , , and

Bombieri's theorem then says that for fixed ,

provided that .

More things to try:

Weisstein, Eric W. "Bombieri's Theorem." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/BombierisTheorem.html