No.  It's a P2SH address.

P2SH addresses can have multisig as the script that was used to generate the hash, however there is no requirement that the spender use a multisig script when spending it.


You wouldn't need to calculate multiple private keys.

You would only need to calculate a SINGLE key pair.  Any private/publick key pair at all would work.  You don't even need to find the original key (or keys) that were used when creating the address.

Then, you would build a script that uses the public key that you generated and a nonce value.  After that, all you have to do is brute force the nonce until the hash of the script (public key + nonce) is equal to the hash used for that address.  On average, it should take you approximately 2¹⁵⁹ attempts.