THANK YOUU!!!
If the company you are mining with is asking for an "account number", then they are almost certainly a scam, and you should probably stop mining with them.
They probably meant to ask for a bitcoin address from a wallet where you can receive bitcoins, but their lack of knowledge about the most basic aspects of bitcoin doesn't not encourage confidence in their ability to operate a legitimate bitcoin based business.
I have to agree with DannyH. If they asked for an "account number", beware. Whatever you do, do not give them your private keys, only the public bitcoin address.