Number of Primes is Infinite/Proof 4

Proof
there exist only a finite number of primes.

From Sum of Reciprocals of Powers as Euler Product:
 * $\ds \sum_{n \mathop \ge 1} \dfrac 1 {n^z} = \prod_p \frac 1 {1 - p^{-z} }$

When $z = 1$ this gives:
 * $\ds \sum_{n \mathop \ge 1} \dfrac 1 n = \prod_p \frac 1 {1 - 1 / p}$

As there exist only a finite number of primes, the  is also finite.

But from Harmonic Series is Divergent, the diverges to infinity.

The result follows by Proof by Contradiction.