Since 6 is the day that man is created and 7 represents the completion of creation and perfection. It may also symbolize the triumph of God's perfection over the imperfection of Man and Satan's attempts to overthrow his plan.
The meaning of numbers such as 777 is derived from it being a number of perfection in the Bible. Today we will check the role of the number 777 in prophecy, worship of God, and His complete forgiveness. Role of the number 777 in the Battle of Jericho The number…www.faithpot.com
And also dont forget the "eighth day" after the Sabbath, (Mark 16:1) which symbolizes the new creation inaugurated by the resurrection of Christ.
I believe this connects with Revelation 13 because just as Neron Caesar written in Hebrew characters is equivalent to 666,
Iesous(Jesus) has a numerical equivalence of 888.