If the product $\left(4^5\right)\left(5^{13}\right)$ is written as an integer, how many digits are in this integer?
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
If the product $\left(4^5\right)\left(5^{13}\right)$ is written as an integer, how many digits are in this integer?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
13
If the product $\left(4^5\right)\left(5^{13}\right)$ is written as an integer, how many digits are in this integer?
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