What two numbers, if multiplied, would generate a 400-digit number?

I need to find 2 prime numbers that, if multiplied, would generate a 400-digit number. Any idea how to go about this. I have all the prime numbers but no matter what I do I do not get 400. Am I looking at this question wrong maybe? Thanks ::confused:

Three primes - p,q, and r- satisfy p+q=r and 1<p<q. What is the value of p? Let a, b, c, and d be integers with a<2b, b<3c and c<4d. If d <100, what is the largest possible value for a?

Hello. I am having an issue figuring out a way to go about this. Here's my scenario: The company I work for uses forms that we can put products, purchased by other companies for each order made. Each form has its own unique WT number. I've been assigned the task of making this form as an excel...

2 numbers if multipied would generate a 400 digit number?