No. The most they can do with a phone number is bombard that phone with text messages and spam calls.
Here's a bit more from a site discussing this issue:
Is It Possible To Hack Someone’s Cell Phone With Just Their Number?
Now that we have discussed the possible reasons why one may need to hack into someone’s cell phone, let’s move ahead. Is it possible to hack a cell phone using just their number? The answer is slightly more complicated than a simple yes or no.
You may be able to hack into an Android phone by using their mobile number. However, you may also need the carrier and device IMEI number.
There’s a catch here; you’d need to physically access the target phone unless you already have it written with you. You can also know the IMEI/MEID number by dialing the universal code *#06# from the target device.
Hacking an iPhone is different from this. In some situations, it may even be virtually impossible to hack into an iPhone using just its phone number.
How to Hack a Phone number on iPhone
This is because hacking into iPhones requires you to enter the target’s iTunes credentials to log into their iCloud. By doing so, you’d be able to retrieve and access relevant data from that device.
Once you have the required credentials, you may not even need their cell number. Another thing to note is that the target device must have enabled the option to allow iCloud backup. Without that, you won’t be able to find the required cell phone data.
Android phones lack a uniform storage app such as iCloud. This mandates you to use a third-party application to be able to access data from an Android phone.
So no. It's not possible with an iPhone. The only known "hack" is to learn both the ID and password of the phone you want to access. And even then, you're not hacking the phone at all. You're getting access to that person's data as if you were them.