When it comes to choosing numbers for any reason, I strongly advise you to always choose 7.
7 is a blessed number.
The number 7 is blessed. It is associated with something “finished” or “complete.” Seven is also associated with divine completeness or perfection. God loves the number seven. The following examples prove what I am saying to you.
Some Scriptures showing that the number 7 is blessed.
Take with you seven pairs of every kind of clean animal.
Genesis 7:2
Then make its seven lamps and set them up on it so that they light the space in front of it.
Exodus 25:37
Observe the Sabbath day by keeping it holy, as the Lord your God has commanded you.
Deuteronomy 5:12
He sprinkled some of the oil on the altar seven times, anointing the altar and all its utensils and the basin with its stand, to consecrate them.
Leviticus 8:11
Then the Lord said to Joshua, “See, I have delivered Jericho into your hands, along with its king and its fighting men. 3 March around the city once with all the armed men. Do this for six days. 4 Have seven priests carry trumpets of rams’ horns in front of the ark. On the seventh day, march around the city seven times, with the priests blowing the trumpets. 5 When you hear them sound a long blast on the trumpets, have the whole army give a loud shout; then the wall of the city will collapse and the army will go up, everyone straight in.
Joshua 6:2-5
My own experience with the number 7.
When God gave me a vision of how Christians can overcome Satan, He used 7 Scriptures: Luke 22:31-32, Job 1:6, Job 2:1, Job 1:9-10, Revelation 12:10, Mathew 4:1, and Luke 11:4. This was the basis of the message in my Book Overcoming Satan in one short sentence.
Always choose the number 7.
Considering all the above, I strongly advise you, whenever there is an opportunity to select numbers, always choose seven OR a combination that has the number seven in it.