Here's one for a start...
Act 1:22 Beginning from the baptism of John, unto that same day that he was taken up from us, must one be ordained to be a witness with us of his resurrection.
Act 1:23 And they appointed two, Joseph called Barsabas, who was surnamed Justus, and Matthias.
Act 1:24 And they prayed, and said, Thou, Lord, which knowest the hearts of all men, shew whether of these two thou hast chosen,
Act 1:25 That he may take part of this ministry and apostleship, from which Judas by transgression fell, that he might go to his own place.
Act 1:26 And they gave forth their lots; and the lot fell upon Matthias; and he was numbered with the eleven apostles.
Here's another...
Act 14:14 Which when the apostles, Barnabas and Paul, heard of, they rent their clothes, and ran in among the people, crying out,
This one infers...
Rom 16:7 Salute Andronicus and Junia, my kinsmen, and my fellowprisoners, who are of note among the apostles, who also were in Christ before me.
There were more than 12 and we really don't know how many. Just because one is not named in scripture, does not mean that one was not an apostle but the above scripture shows at least 14 and probably 16.