Question 124
For a positive integer $n$ write down all its positive divisors in increasing order: $1 = d_1 \lt d_2 \lt \dots \lt d_k = n$.
Find all positive integers $n$ divisible by $2019$ such that $n = d_{19} \cdot d_{20}$.
Find all positive integers $n$ divisible by $2019$ such that $n = d_{19} \cdot d_{20}$.