what would happen if igneous rock was first exposed to energy from the sun and then millions of years later to energy from Earth's interior?

They would become igneous rocks

Explanation:

If originally, sedimentary rocks are exposed to energy from the sun, no changes will occur to them.

One will hardly spot any difference in their mineralogical composition as such.

The temperature of the sun does not any significant alteration on earth materials.

The heat from the interior has a very significant effect on rocks, especially sedimentary rocks.

Heat from the interior can reach a staggering 6000°C which is more than enough to cause a metamorphic change in a body rock.

In fact, at this temperature, igneous rock will be produced from the sedimentary rock.

81 is a composite number.