10+13+2006=13 1+3=4 which has a good solid base as in the pyramid. And, now, for a bit of trivia about the number four:
Four derives its significance from various sources. It is the first "composite" number; that is to say, the first number that can be created from multiplying numbers other than itself and 1, in that 2 X 2 = 4. The simplest solid object — a tetrahedron — has four sides; hence four denotes solid matter in general and the Earth in particular, as the Earth is a solid object bounded by four cardinal points (North, South, East and West). Time is another concept strongly associated with four, on the grounds that the year has four seasons and the month has (roughly) four weeks; Christian-oriented observers also note that the life story of Jesus is told in four gospels , each of which is in turn linked to one of the four classical "elements" of fire, air, earth, and water. Specifically, the Gospel according to St. Matthew is associated with earth since his Gospel stresses Christ's incarnation in earthly form; water is accorded to St. Mark since his Gospel emphasizes the importance of baptism , fire is ascribed to St. John since his Gospel is the most "spiritual," and air is assigned to St. Luke since his Gospel is the longest. The association with Earth means that four symbolizes being practical and "down-to-earth," while the fact that four is the first composite number is linked to the idea of an other-directed, "composite personality" that takes cues from different and often conflicting sources, leading to fiercely independent, "out-of-the-box" thinking. In the Jewish religion, the number four is significant because of the Tetragrammaton , the four-letter name of God which is so holy it is never spoken. In Chinese numerology (as well as that of other Oriental languages), the word "four" is a homonym of the Chinese word for "death" (see Tetraphobia ). As thus, some hospitals do not have a fourth floor.