We study the main cosmological properties of the agegraphic dark energy model at the expansion and perturbation levels. Initially, using the latest cosmological data, we implement a joint likelihood analysis in order to constrain the cosmological parameters. Then, we test the performance of the agegraphic dark energy model at the perturbation level and we define its difference from the usual Lambda cold dark matter (CDM) model. Within this context, we verify that the growth index of matter fluctuations depends on the choice of the considered agegraphic dark energy (homogeneous or clustered). In particular, assuming a homogeneous agegraphic dark energy, we find, for the first time, that the asymptotic value of the growth index is γ ≈ 5/9, which is close to that of the usual cosmology, γ () ≈ 6/11. Finally, if the distribution of dark energy is clustered, then we obtain γ ≈ 1/2 which is ∼8 per cent smaller than that of the CDM model.
