A perfectly reflecting mirror of mass $M$ mounted on a spring constitutes a spring-mass system of angular frequency $\Omega$ such that $\frac{4 \pi \mathrm{M} \Omega}{\mathrm{h}}=10^{24} \mathrm{~m}^{-2}$ with h as Planck's constant. N photons of wavelength $\lambda=8 \pi \times 10^{-6} \mathrm{~m}$ strike the mirror simultaneously at normal incidence such that the mirror gets displaced by $1 \mu \mathrm{~m}$. If the value of N is $\mathrm{x} \times 10^{12}$, then the value of x is $\_\_\_\_$ . [Consider the spring as massless]