The Death of the Egyptian First Born Sons

One thing that bothers me about people who take the bible literally is the story of the first passover. I am bothered that no one seems to care about the number of Egyptian males that must have died to prove that Yahweh is all powerful. According to Wikipedia, "Egypt at the time might have supported a total population of around 3-4 million, maybe even up to 6 million." Simple chance (50 out every 100 births is a male) tells us that at least half of the population should have been male, some 1.5 - 2 million upwards to 3 million males. Chance tells us that at least half of these males should be first born son. So, according to Exodus, some 750,000 to 1.5 million first born males were killed by the angel of death at the first passover. Of course the number may not be that high as not every male would be of child producing age or have had enough children to have had at least one son. What we can agree on is that a very large number, in the hundreds of thousands, of male children were supposedly killed. I have never seen any historical evidence of that many males dying at one time. Where is the evidence? One would think that somewhere in Egyptian history someone would have recorded this kind of disaster. Has a mass grave with this many mummies or bodies ever been found? Is there evidence of the economic disaster that would have befallen Egypt with this many deaths? If the bible is to be taken literally, where is the evidence? This is another example of why the bible cannot be taken literally, because logic and reason tells us that if that many males were killed, there must be mass graves, or someone must have written another independent account of what happened. Show me evidence of a mass grave or mass mummies, or historical records apart from the bible, and I will be less skeptical.