The phrase "prodigious number" means an extremely large or impressive amount. It refers to a quantity that is very big, remarkable, or extraordinary. Full definition
The machine will produce familiar particles in prodigious numbers (several top quarks per second, for example) and scrutinize them with increasing refinement. (scientificamerican.com)
A master class in how to keep multiple plot lines with a prodigious number of moving parts in play, it's a major storytelling achievement. (startribune.com)
Still, it doesn't take a prodigious number - cruncher — lucky, since I'm not one — to tell that this is quite a result for «The Help.» (incontention.com)