That's the ratio of 4,126,532 to 1,000,000 so it's rational.
Here's a little factoid that I never see mentioned anywhere, but I think it can be really helpful to know:
==> Any number that you can WRITE DOWN COMPLETELY using digits (plus a decimal point or a fraction bar if you need them) is a rational number.
If " 4.126532 " is the whole thing, you sure nuff wrote it down, so it's rational.