54 (number)

Also, 54 is a regular number, and its even division of powers of 60 was useful to ancient mathematicians who used the Assyro-Babylonian mathematics system.

Like all multiples of 6,[3] 54 is equal to some of its proper divisors summed together,[a] so it is also a semiperfect number.

[4] These proper divisors can be summed in various ways to express all positive integers smaller than 54, so 54 is a practical number as well.

Using the Pythagorean theorem, there is no way to construct 542 as the sum of two other square rational numbers.

To convert from the former to the latter, the result's representation is interpreted as a number shifted three base-60 places to the right, reducing it by a factor of 603.

[18] In The Hitchhiker's Guide to the Galaxy by Douglas Adams, the "Answer to the Ultimate Question of Life, the Universe, and Everything" famously was 42.

[19] Eventually, one character's unsuccessful attempt to divine the Ultimate Question elicited "What do you get if you multiply six by nine?

Three stacks of 54 cubes. Each stack is composed of three tiers. Each tier contains a number of cubes arranged in a square.
54 as the sum of three positive squares
The Ellingham–Horton 54-graph
These symbols are abstract geometry that does not directly map onto the numbers' values. The core feature is that they all involve at least five vertical parallel lines. For example, 2 is just five vertical parallel lines that do not touch. 53 is those five lines connected at the top. 54 is all of the lines connected, alternating top and bottom, so it looks like a winding snake.
Genji-mon , the traditional symbols that represent the fifty-four chapters of The Tale of Genji