The rated Watts of a an amp is its rated output power, not what it draws from the plug, it could be more.
Example: if you connect 4 or 2 ohm speakers to a amp that has 8 ohm you will get 2 or 4 times the output level, meaning very loud music
Warning: Doing that could damage amp and speakers.
There are many things to consider when looking at amps besides just the watt output. What load is it designed for, what is the power supply made of.
This is a good read.
Even if you had a 1,000 Watt Amp, would it sound good or just distort out when played at high volume.