discord.js how many servers ur bot is in code example

Example 1: how to see in how many servers your discord bot is d.js

You need to use client.setActivity() and then use the client.guilds.cache.size value. 
For example:

client.setActivity(`Currently in ${client.guilds.cache.size} servers`);

Example 2: how to display server count on discord.js

module.exports.run = async (client, message, arguments) => {
   const guild = client.guilds.get("566596189827629066");
   setInterval(function () {
      var memberCount = guild.members.filter(member => !member.user.bot).size;  
      var memberCountChannel = client.channels.get("626462657817477131");
      memberCountChannel.setName(`${guild.name} has ${memberCount} members!`);
   }, 1000);
};