There is the spirit of the anti-spirit specifically identified in scripture, and there is anti-christ[s] plural that are out there....but Revelation plainly says there is a singular anti-christ, a man, with the calculated number of 666 that it describes.
"Here is wisdom. Let him that hath understanding count the number of the beast: for it is the number of a man; and his number is Six hundred threescore and six."
Revelation 13:18