May Make $\frac5{2020}$ 2020

Question

For May 2020, try to create $\dfrac{5}{2020}$ using the least possible number of integers in the set $\{1,3,4,6,7,8,9\}$.

$2$, $5$ and $0$ are not allowed.

Example:

$$\dfrac{4+1}{3\left(673+\frac13\right)}$$

Uses $1,1,3,3,3,4,6$ and $7$ $\implies$ $8$ numbers. You must do better than $7$ numbers.

You are allowed to use any operation as long as you can find a wikipedia page created before 2020, that's why there is a lateral thinking tag.

Improving puzzle - thanks to @athin's answer and @Daniel Mathias' comments Any mathematical constant apart from $\{1,3,4,6,7,8,9\}$ is not allowed!

$$\dfrac{\lfloor \phi \rfloor}{\lceil e^{\lfloor \pi + \pi\rfloor}\rceil} $$

is equal to $\frac{5}{2020}$ but it's not a valid solution!

Answer 1

Using the good ol' functions like:

ceiling and exponential functions.

Here is a way with only just two digits!

$$\frac{1}{\lceil \exp(6) \rceil} = \frac{1}{404} = \frac{5}{2020}$$

Answer 2

Here is a way to do it with four digits

$$\frac{5}{2020} = \frac{1}{8!! + 4! - 4} $$ where we have used double factorial

Here is a way to do it with three digits

$$ \frac{5}{2020} = \frac{1}{8!! + \sigma(\sigma(8))} $$ where $\sigma$ is the Divisor sum function

Answer 3

Improved solution:

See Home prime.
$\frac{1}{93+HP(9)}=\frac{1}{93+311}=\frac{1}{404}=\frac{5}{2020}$

Straightforward solution:

Using five digits, $\frac{4}{1616}=\frac{5}{2020}$

Answer 4

Using

string concatenation (here denoted by $\otimes$, e.g. $2\otimes5=25$), Wikipedia page about it was created in 2002 and even last modified in 2019

we can get

$$\frac1{4\otimes(6-6) \otimes 4}=\frac1{404}=\frac5{2020}$$.

Answer 5

This uses four digits as well:

$$\frac{1}{4 \cdot p(13)}$$

where

$p(n)$ is the number of distinct integer partitions of $n$.