A multiplication expression with a product of $5^{13}$ can be written as:

$5 \times 5 \times 5 \times 5 \times 5 \times 5 \times 5 \times 5 \times 5 \times 5 \times 5 \times 5 \times 5$

This is essentially multiplying the number 5 by itself 13 times, which gives the product of $5^{13}$.

Would you like any further details or have questions about this? Here are some related questions:

1. How do you simplify expressions with exponents?
2. What is the value of $5^{13}$?
3. How can exponents be used in solving real-world problems?
4. What are the rules for multiplying powers with the same base?
5. How do you express large numbers using exponents efficiently?

Tip: Remember that multiplying a number by itself multiple times is the same as raising it to a power (exponentiation).