How to reboot an android device without using power button? Unfortunately, the power button doesn't work and I'm not able to power off the device.

The only way, is physically pull out the battery, but if I'll do so, I wont be able to power it on again.

The cellular network doesn't work , and the Wi-Fi seems to, too.

The device is up for 53:21:59 hours!! (and seems to count..)

I must force somehow a reboot.

Is there shell command (and if so - how to access it?) , or application that forcing reboot? 

Thanks.
If you can connect using adb (usb debugging), you can simply use the command "reboot".

If you're rooted and have a terminal emulator installed, "su reboot" will do the same thing.

The reboot command will also accept arguments of "recovery" or "bootloader", which will reboot you into the recovery or bootloader respectively.