A particle of mass $9.1 \times 10^{-31} \mathrm{~kg}$ travels in a medium with a speed of $10^6 \mathrm{~m} / \mathrm{s}$ and a photon of a radiation of linear momentum $10^{-27} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$ travels in vacuum. The wavelength of photon is $\_\_\_\_$ times the wavelength of the particle.