This is Makikomarete Isekai Teni suru Yatsu wa, Taitei Cheat, also identified here and here.
One day 's lunch break, suddenly a male high school student Yuzo Ogata who has been transferred to another world of sword and magic together with four other friends. According to the Princess of Space-Time Magician, a foreign world who summoned them, they want them to beat the Demon Lord as Heroes to save this world. Suddenly I was surprised at four friends "Temple", but it was a relaxing expression ... ... where the princess told of a startling fact!" "―There should only be four braves though?" A man who was mistakenly summoned to a different world.
The synopsis covers the "extra" bit - five people were summoned, but there should only have been 4. The MC does not apparently have any special powers - for example, he's barely able to lift the weapons the others use with ease.
He gets attacked and kidnapped by a mud monster and suddenly finds himself in a temple with a regular desktop computer.
This awakens his godlike powers, which he uses to save a slave trader from bandits, and purchases a slave girl.
I didn't see any exponential notation in his stats while reading through this.
Found by searching mangaupdates for the tags
Transported to Another World,