All those figures are made up. Nobody knows how hot the Sun is.
How do you measure how hot the sun is if you can't get that close to measure?
One way is to study the sun's spectrum — that is, break up its light with a prism. A rainbow is a spectrum created when sunlight goes through raindrops, which act as little prisms. If we do this with a special device called a spectrograph, we can see that there are thin dark lines throughout the sun's spectrum. Scientists have examined the different elements on earth, so we are able to figure out what kind of gas, say hydrogen, gives rise to which dark lines. It turns out that every element has a unique set of dark lines, like fingerprints. We can use them to figure out what the sun and stars are made of. They also show us how hot the gases are.
Another way is to look at sunlight and measure how much light is in the blue part of the spectrum, in the yellow, in the red. The hotter something is, the more light it gives off in the blue compared to the red. All these methods show us that the sun's surface is about 10,000 degrees Fahrenheit!
I mean even if you don't think it's accurate. You really think these nikkas sitting around in an office throwing darts at random numbers like YEAH. That's how hot the sun is.