# The Number 18: Properties and Meanings

Prime Factors of**18**=2x3x3.

**18**is a Pentagonal Pyramidal Number.

**18**is a Heptagonal Number.

**18**is an Abundant Number.

**18**=3 + 4 + 5 + 6.

**18**is a Lucas Number.

**18**can be Partitioned in 385 ways.

**18**can be Partitioned 10 times with each term no larger than 2

**18**can be Partitioned 37 times with each term no larger than 3

**18**can be Partitioned 84 times with each term no larger than 4

**18**can be Partitioned 141 times with each term no larger than 5

**18**can be Partitioned 199 times with each term no larger than 6

**18**can be Partitioned 248 times with each term no larger than 7

**18**can be Partitioned 288 times with each term no larger than 8

**18**can be Partitioned 318 times with each term no larger than 9

**18**can be Partitioned 340 times with each term no larger than 10

**18**can be Partitioned 355 times with each term no larger than 11

**18**can be Partitioned 366 times with each term no larger than 12

**18**can be Partitioned 373 times with each term no larger than 13

**18**can be Partitioned 378 times with each term no larger than 14

**18**can be Partitioned 381 times with each term no larger than 15

**18**can be Partitioned 383 times with each term no larger than 16

**18**can be Partitioned 384 times with each term no larger than 17

The

**18**Regular Solids: the 5 Platonic Solid + the 13 Archimedean Solids.

A Truncated Tetrahedron is an Archimedean Solid with

**18**Edges.

**18**is the only number that is twice the sum of its digits.

The Chemical Element Argon has an atomic number of

**18**.

The alphabet of the trees used by the druids for divinatory uses had

**eighteen**letters, each letter deriving its name from the tree of which it is the initial. Composed of 5 vowels and 13 consonants, it formed a seasonal magic calendar of trees.

**18**Melpomene is a large, bright Main belt asteroid named after Melpomene, the Muse of tragedy in Greek mythology. .

### The Year 18 AD

In the year**18**AD Caiaphas became the high priest of Jerusalem.

In the year

**18**AD Strabo wrote

*Geographia*