We know that c/lambda is frequency of photon. Now, my question is, we are considering photon as a particle, so how come it has wavelength which is the characteristic property of wave? Here,Light is behaving in particle nature that is why we have quantum physics. So, what does it mean by WAVELENGTH of PHOTON?
According to the Quantum Physics, photons have dual nature: they are observed as waves participating in some phenomenons (like interference) and particles during others (like Compton's phenomenon) but never both at the same time. When we consider photons as quantum portions of waves, they have frequencies proportional to their energy (where coefficient is simply Planck constant).
Of course every piece of matter has the same property (protons, electrons, even me and you). For every particle of momentum p you can calculate de'Broglie wavelength of it, please see: Wikipedia article. When the mass is huge and so the wavelength become small, wave properties become very hard to observe, so big pieces of matter behave simply like particles as we observe it everyday.