An npn BJT having reverse saturation current $I_{S} = 10^{-15}\:A$ is biased in the forward active region with $V_{BE} = 700\: mV.$ The thermal voltage $(V_{T})$ is $25\: mV$ and the current gain $(β)$ may vary from $50$ to $150$ due to manufacturing variations. The maximum emitter current $(\text{in}\: \mu A)$ is ________.