Singer was good at stamping numbers on everything! So unless you know where to look (especially on the less old machines) it can be real easy to find the wrong number.
The number on this machine may be on the underside, and you may have to take off a cover plate before you'll be able to see it. That is if it's not in the usual base of the pillar spot - all depends on the model -could be a 15, or a 66, or a 99, or a 201, or even a 301 or 401, and maybe a FW (221).
However, if it's got an external motor (since those probably are numbers off a motor), that rules out the 301 and 401, so unless it's a FW, the serial number should beat the base of the pillar.
Kind of fun to play "what model is this" with very little information. A picture is the easiest way to tell though - Singer made them all rather unique. Well, except for the 15 and 115, but yours is too new to be a 115.