For the decomposition of azomethane.
$\mathrm{CH}_3 \mathrm{~N}_2 \mathrm{CH}_3(\mathrm{~g}) \rightarrow \mathrm{CH}_3 \mathrm{CH}_3(\mathrm{~g})+\mathrm{N}_2(\mathrm{~g})$ a first order reaction, the variation in partial pressure with time at 600 K is given as

The half life of the reaction is $\_\_\_\_$ $\times 10^{-5} \mathrm{~s}$. [Nearest integer]