The 555 has 8 pins...
network electronics
40 PINS
The 7805 regulator IC has three pins; input, output, and ground. The case is also a pin, but it is grounded, so there are still only three pins, for all practical purposes.
Originally designed as a timer it has dozens of possible uses:timerflipfloppulse width modulatorpulse position modulatoretc.
it have 40 pins 1st one is ground and last one is Vcc. Itplh = 450
8-pin 555 timer IC
for simplicity of calculation of no of pins
IC pins are numbered anti-clockwise around the IC starting near the notch or dot.
these two pins are biasing pins of ICs.
IC's which starts from 7 are most of them are digital ic's . not all the IC's starts with 7 for example LM380 audio IC CTC810 audio amplifier ic and lm317 voltage regulator ic ,NE555 timer ic, 4017 counter and so other. there are no fact behind them . 7400- nand 7402 -nor 7404-not 7408-and 7432-or 7486-exor 74266-ex-nor 74147 priority encoder.
The IC 555 is often referred to as NE555 because "NE" stands for "National Semiconductor," the company that originally introduced the device in 1972. The designation "555" refers to the specific model number of the timer integrated circuit. Over time, the NE555 became widely adopted and is now a generic term for this type of timer circuit, with various manufacturers producing compatible versions.
to avoid floating pins ...........so as to avoid rail to rail current