Two Primes = A 400 digit number

It seems that any number with 300 or more digits seems very hard to get. How can I find two prime numbers that if multiplied, I'll get a 400 digit number?

You know, I looked at both those equations for a couple minutes and couldn't for the life of me figure out what the difference was until >>8 pointed it out.

$brain =~ s/x/\*/;