Problem 738

【Solution】Solution: Test $\frac{3}{13} \approx 0.2307692308, \frac{33}{13} \approx 2.5384615385, \frac{333}{13} \approx 25.615384615 \cdots \frac{333333}{13}$ $=25641$,

Therefore, the result of dividing this 1994-digit number by 13 is: 25641 in a cycle. (ignoring the decimal part), so $200 \div 6=33 \cdots 2$,

The 200th digit (counting from left to right) of the quotient is 5;
$$1994 \div 6=332 \cdots 2 \text {, }$$
The result of $33 \div 13$ is $33 \div 13=2 \cdots 7$,
From this, we can know that the unit digit of the quotient is 2 and the remainder is 7.
Answer: A 1994-digit number, where each digit is 3, when divided by 13, the 200th digit (counting from left to right) of the quotient is 5, the unit digit of the quotient is 2, and the remainder is 7.

Therefore, the answers are: $5, 2, 7$.