Properties of the number 73

Symbolism

It is the number of what is completed, which forms a unit complete perfect, in which each parts interacts harmoniously with the others while preserving its autonomy.

The 73 sects resulting from the division of the community of the Prophet: sixty twelve have perished, one was saved.
The Chinese medicine divides the year into four seasons of 73 days and four interseasons of 18 days. Although this division does not correspond to any astronomical reality, the Chinese medicine uses it to treat the sick organs during the season where they receive a surplus of energy allowing it to exert more easily its functions. For example, the liver will be specially treated during 73 days in the spring, the heart during 73 days the summer, just as the lung to the autumn and the kidney in winter. The spleen is treated during the 18 days of interseason separating the summer and the autumn.
Among the abbreviations used in telegraphy and telephony, and which are employed universally, we find the number 73 that has for meaning "best regards". For example, the radio hams, just as the user of citizen band radio (CB), often use it to finish a conversation.

Numerical value of the word "Jesod" (Basis) of the sephirotic Tree of the Cabal, according to Abellio.
In Isaiah 44,6 and 48,12, Yahweh declares: "I am the first and I am the last". In Hebrew, "first" gives 73=20+1+21+6+25 by using the gematria in "n".