The prime factorisation of 2020 is 2020=4⋅5⋅101 and so a complete list of divisors of 2020 is:
d1d8=1,d2=2,d3=4,d4=5,d5=10,d6=20,d7=101,=202,d9=404,d10=505,d11=1010,d12=2020.
The required properties, 2020=d3d4d7 and d3d4<d7, are now easy to check.
As N=d3d4d7, the product d3d4 is a divisor of N, which was assumed to be smaller than d7. Hence d3d4=d5 or d3d4=d6. We first exclude that d3d4=d5. In this case, N=d3d4d7=d5d7 and the number of divisors of N is equal to 11. Because the number of positive divisors of N=∏piei is equal to ∏(ei+1), any number with exactly 11 divisors must be of the form N=p10 where p is a prime number. But then d3=p2, d4=p3 and d5=p4 and so d3d4=d5. This shows that we must have d3d4=d6. Then N=d3d4d7=d6d7 and N has 12 divisors.
As 12=6⋅2=4⋅3=3⋅2⋅2 we have to consider the following four cases: N=p11, N=p5q, N=p3q2, N=p2qr where p,q,r are distinct primes.
N=p11: In this case, d3=p2, d4=p3 and d7=p6, and we see that N=d3d4d7 as well as d3d4<d7 as required.
N=p5q: We have 1<p<p2<p3<p4<p5 and we can order the divisors of N once we know the size of q. There are six possibilities

and we easily check that d3d4<d7 holds when 1<q<p and when p5<q.
N=p3q2: We will investigate all possibilities for d6d7=p3q2 and check if d3d4=d6. The pairs {di,d13−i}, whose product is N, are the following:
{1,p3q2},{p,p2q2},{p2,pq2},{p3,q2},{q,p3q},{pq,p2q}.
Because p3q2, p2q2 and p3q have more than 7 factors, these cannot be equal to d6 or d7, so we have only three options to consider for {d6,d7}, namely {p2,pq2}, {p3,q2} or {pq,p2q}.
If {d6,d7}={p2,pq2}, then d6=pq2 and d7=p2, because we cannot have d6=p2=d3d4 as d3>1. From pq2=d6<d7=p2, we get q2<p. Hence, the divisors of N need to satisfy
1<q<q2<p<pq<pq2<p2<p2q<p2q2<p3<p3q<p3q2.
We see now that d3d4=d6 and we get a working solution.
If {d6,d7}={p3,q2}, then d6=p3 and d7=q2, because we cannot have d6=q2=d3d4 as d3>1. The equation p3=d6=d3d4 can only be achieved with d3=p and d4=p2. This implies d2=q and so 1<q<p<p2. But then d3=p<pq<p2=d4, a contradiction.
If {d6,d7}={pq,p2q}, then d6=pq<p2q=d7, and pq=d6=d3d4 could only be achieved with d3=p,d4=q or d3=q,d4=p. Both are impossible as there would be no option left for d2.
N=p2qr: We may assume that 1<q<r<qr. Because p2q has six divisors and all other divisors of N are multiples of r, dk=r for some 3≤k≤7.
If d7=r, then d6=p2q and we automatically have d6=d3d4 as p2q has six divisors. This case occurs precisely when p2q<r.
If d6=r, then d6=d3d4 is impossible as d3>1.
If d5=r, then d8=p2q and d6,d7 must form one of the pairs {p,pqr}, {pq,pr}, {p2,qr}. The first of these three is impossible, as p<pq<pr<pqr. Secondly, when d6=pq<pr=d7, pq=d6=d3d4 could only be achieved with d3=p,d4=q or d3=q,d4=p. Both are impossible as there would be no option left for d2. For the third option we first note that d6=p2 can be ruled out as before using d6=d3d4. However, d6=qr is impossible as well, because d5=r and we again get a problem with d6=d3d4.
If d4=r, then d2=p or d3=p. In the first case we would have 1<p<q<r and so d6=d3d4=qr, which implies d7=p2. However, we have p2<pq<pr which would mean that both members of the pair {pq,pr} are larger than d7, contradiction. In the second case, we would have 1<q<p<r and so d6=d3d4=pr, which implies d7=pq. But q<r implies d7=pq<pr=d6, contradiction.
If d3=r, then d4=p because d6=d3d4 cannot be divisible by r2. We get d6=pr and d7=pq. But q<r implies d7=pq<pr=d6, a contradiction.
To summarise, the complete list of solutions is: