How many people can join the meeting using the phone number function only?

I would like to hold a meeting with 70 people who only dial in using the phone number function. So more like a conference call than a video conference. How many people can join?

Jitsi-Meet is a video conferencing solution. There is no point of doing audio conferences through it. If you are looking to deploy somthing you can try asterisk or freeswitch.
If you are asking about meet.jit.si, the limitations are the same as normal participants, up to 75 …