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


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