Finding minimum energy distribution of N charges on a sphere has been known as the Thomson problem. Here, we study the vibrational properties of the N charges in the lowest energy state within the harmonic approximation for 10 ≤ N ≤ 200 and for selected sizes up to N = 372. The maximum frequency ωmax increases with N 3/4 , which is rationalized by studying the lattice dynamics of two-dimensional triangular lattice. The N -dependence of ωmax identifies magic numbers of N = 12, 32, 72, 132, 192, 212, 272, 282, and 372, reflecting both a strong degeneracy of one-particle energies and an icosahedral structure that the N charges form. N = 122 is not identified as a magic number for ωmax because the former condition is not satisfied.