find 2 prime numbers that if multiplied would generate a 400 digit number

I'm not sure what you want. 400 is a three-digit number, and 4000 is a four-digit number. I don't think you want a "400 digit number."

Assuming you want a number with a value over 400, this site will be helpful:

http://mathforum.org/dr.math/faq/faq.prime.num.html

I hope this helps. Thanks for asking.

To find two prime numbers that, when multiplied, would generate a number with over 400 digits, you can use the following approach:

1. Start by determining the number of digits you need. If you want a number with more than 400 digits, you'll need at least half that number of digits for each prime number. In this case, let's assume you want a number with 400 digits, which means each prime number should have around 200 digits.

2. One way to find large prime numbers is by using a prime number generator or a prime number database. These tools can help you find prime numbers of a certain length. You can search online for "prime number generator" or "prime number database" to find reliable resources that suit your needs.

3. Once you have access to a prime number generator or database, search for prime numbers that have around 200 digits. Note down two prime numbers of similar lengths.

4. Multiply the two prime numbers together. This will give you a product that consists of approximately 400 digits.

Remember that finding prime numbers with such a high number of digits is extremely challenging. It may require specialized tools or algorithms, and it can be a computationally intensive task. Consider using pre-existing prime number databases or consult with experts in number theory if necessary.