The character for "umbrella" is hieroglyphic, but it doesn't actually represent the shape of one.It's actually "five people gathered around bones arranged as a cross".
In other words, it represents a ritual.And then, if you roll it up, you can see the form of the number 1.The bones form the kanji for "seven".One character used to write "three" can also mean "to gather".
1
3
7
These are the numbers contained by an umbrella.In addition, all these numbers are odd.If you look at this umbrella again, you can see that umbrellas have evolved without changing their shape. As if to symbolize the number 3, which is the number of stability, and other characters with the same reading.