A. Fix δ P p0, 1s, σ 0 P r0, 1q and a real-valued function εpxq for which lim xÑ8 εpxq ď 0. For every set of primes P whose counting function π P pxq satisfies an estimate of the formwe define a zeta function ζ P psq that is closely related to the Riemann zeta function ζpsq. For σ 0 ď 1 2 , we show that the Riemann hypothesis is equivalent to the non-vanishing of ζ P psq in the region tσ ą 1 2 u. For every set of primes P that contains the prime 2 and whose counting function satisfies an estimate of the form π P pxq " δ πpxq`O`plog log xq εpxq˘, we show that P is an exact asymptotic additive basis for N, i.e., for some integer h " hpPq ą 0 the sumset hP contains all but finitely many natural numbers. For example, an exact asymptotic additive basis for N is provided by the set t2, 547, 1229, 1993, 2749, 3581, 4421, 5281 . . .u, which consists of 2 and every hundredth prime thereafter.