How to make a bot stop a certain action and not close?

Question

So here's my code.

# simple bot.
import random, discord, os, time, ctypes
from xmlrpc.client import MAXINT
from time import sleep
bot_token = "BOT TOKEN"
local_time = time.ctime(time.time())
randnum_bot = discord.Client()
@randnum_bot.event
async def on_ready():
    guild_count = 0
    print("""randomnum bot has started running.
Current time: """ + local_time)
    for guild in randnum_bot.guilds:
        guild_count += 1
        print("randomnum bot is in " + str(guild.name))
@randnum_bot.event
async def on_message(message):        
    if(message.content == "!generatenum"):
        random_time_interval = random.randint(0, 5)
        random_times = random.randint(0, 100)
        await message.channel.send(f"A random number will be generated every {random_time_interval} seconds for {random_times} times.")
        for i in range(random.randint(0, 100)):
            await message.channel.send(random.randint(0, MAXINT))
            sleep(random_time_interval)
randnum_bot.run(bot_token)

Put simply, this Discord bot generates a random number for a random amount of times within a random interval of time.

But here's the thing: I want to make the bot cease all of its activities(and remain online) once a certain message is sent, for example a !stop message.

I tried adding an elif in the on_message function, and I did it like this:

@randnum_bot.event
async def on_message(message):        
    if(message.content == "!generatenum"):
        random_time_interval = random.randint(0, 5)
        random_times = random.randint(0, 100)
        await message.channel.send(f"A random number will be generated every {random_time_interval} seconds for {random_times} times.")
        for i in range(random.randint(0, 100)):
            await message.channel.send(random.randint(0, MAXINT))
            sleep(random_time_interval)
    elif(message.content == "!stop"):
        await message.channel.send("Alright, see you next time!")
        await randnum_bot.close()

Although it does make the bot stop once a message that contains !stop is sent, it actually makes the bot go offline, which is really inconvenient. I also tried inserting await randnum_bot.run(bot_token) after await randnum_bot.close(), but that resulted in an error which was RuntimeError: Cannot close a running event loop.

Is there a way to make a bot stop its activities, without actually making it go offline?