Seven or 7 

Seven is the number that follows Six and is before Eight on a number line.

There are now Seven Days of a Week.

There were Seven wonders of the ancient world.

At one time mankind considered there to be Seven Planets.

There are Seven Hermetic Principles. 

There are Seven Liberal Arts.

Seven is a prime number.

Rolling a Seven on the first roll of a pair of dice in a craps game is a win for the person who is rolling the dice at the time.

Seven is the only one of our single digit numbers that does not divide evenly into the 360 degrees of a circle.

Seven is about 1/4 of a lunar month.

The information between these two horizontal lines was copied from somewhere but I do not remember where since I neglected to save the source.  I make no claim as to this info.  It is someone else's work.  I included it since I found it interesting. Not knowing who to contact I did not ask or receive permission.  If you own it and wish it removed please contact me.

The Mystical Number Seven

Perhaps the numeral seven is considered the most mystical of all numbers because it is the one number which cannot be divided evenly into the circle. This is always a dividend as the following chart illustrates:

Further references to the numeral seven:

The dividend from the division of the circle by the number seven is intriguingly close to the outer angle of the Great Pyramid: 51 degrees and 51 minutes.

The mystical nature of Pi: The number 22 is considered symbolic of a complete circle, or the circle, because this is reflected by the twenty-two letters in the Hebrew alphabet, the twenty-two keys in the Major Arcana of the Tarot (Keys 1 - 21, plus The Fool) and indicating the full circle of experience. The function 22/7, one cycle of human experience divided by the spiritual Seven or Divinity within. This function is the value of Pi; or, the closet to it as can be expressed in whole digits. The discovery of Pi was a significant breakthrough in mathematics because its value is the relationship between the circumference of a circle and its radius and diameter; Pi presented humankind with a formula by which these things might be easily measured. A.G.H.

Source:
Bunker, Dusty, Numerology, Astrology and Dreams, West Chester, PA, Whitford Press, 1987.