You cannot know, to which type an address of "3QJ...inyC" belongs, unless you created it yourself, or had the underlying data. Such a "type 3" address can be a hash of any data :-)
Ok, to be more precise for multisig: the address is probably created out of a redeem script (e.g. for a 2-of-3 multisig: <2><3>). This redeem script is hashed, and as a hash is a one way function (as per today's knowledge), you cannot reverse it.
You might have the chance to see which msig addresses / pubkeys and number of required sigs are included, when the spending transaction has been mined. Then you see all details of the redeemscript in the sigscript.
The way it works is described here: https://github.com/bitcoin/bips/blob/master/bip-0016.mediawiki. Much more details can be find in chapter 5 of Andreas' book "Mastering Bitcon, 2nd edition".