54 (number)

← 53 54 55 →
← 50 51 52 53 54 55 56 57 58 59 → List of numbers Integers ← 0 10 20 30 40 50 60 70 80 90 →
Cardinal	fifty-four
Ordinal	54th (fifty-fourth)
Factorization	2 × 33
Divisors	1, 2, 3, 6, 9, 18, 27, 54
Greek numeral	ΝΔ´
Roman numeral	LIV
Binary	1101102
Ternary	20003
Senary	1306
Octal	668
Duodecimal	4612
Hexadecimal	3616
Chinese numeral	五十四

54 (fifty-four; LIV) is the natural number following 53 and preceding 55. An even number and a composite number, 54 is divisible by 1, 2, 3, 6, 9, 18, 27 and 54.

In mathematics

Number theory

54 as the sum of three positive squares

• 54 is an abundant number and a semiperfect number, like all other multiples of 6.
  • An Aliquot sum of 66
• It is twice the third power of three, 3³ + 3³ = 54, and hence is a Leyland number.
• 54 is the smallest number that can be written as the sum of three positive squares in more than two different ways: 7² + 2² + 1² = 6² + 3² + 3² = 5² + 5² + 2² = 54.
• It is a 19-gonal number,
• The number of primes ≤ 2⁸.
• A Lehmer-Comtet number.
• 54 is the only non-trivial Neon Number in Power 9: 54⁹ = 3,904,305,912,313,344; 3 + 9 + 0 + 4 + 3 + 0 + 5 + 9 + 1 + 2 + 3 + 1 + 3 + 3 + 4 + 4 = 54
• A humble number

Trigonometry

• The sine of an angle of 54 degrees is half the golden ratio.

Graph theory

• The Holt graph has 54 edges.

Recreational mathematics

• In base 10, 54 is a Harshad number.
• Aban number
• Eban number

Traditional Japanese symbols of the 54 chapters of the Tale of Genji

List of basic calculations

Multiplication	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
54 × x	54	108	162	216	270	324	378	432	486	540	594	648	702	756	810	918	972	1026	1080	1134

In other fields

In chemistry, 54 is the atomic number of xenon, a noble gas. In astronomy, the Messier object M54 is a globular cluster in the constellation Sagittarius. NGC 54 is the designation of a spiral galaxy in the constellation Cetus. There are 54 years and 34 days in three Saros cycles of eclipses of the Sun and moon, which is known as a "triple Saros" or an exeligmos (Greek: "turn of the wheel"). In ASCII, 54 is the decimal for the number 6 character.

With regards to sports, in golf, a score of 54 on a par 72 course is colloquially referred to as a perfect round. This score has never been achieved in competition. In racquetball, 54 is used when a player is defeated 3 games in a row.

"54" has been used to title art projects. The 1998 film 54 was a biopic about a famous nightclub called Studio 54. The Wu Ming collective wrote an unrelated novel called 54, which was set in 1954. Additionally, a television show called Car 54, Where Are You? aired in the 1960s and received a film adaptation in 1994; the title referred to the call sign of the main characters' police car.

A famous joke from The Hitchhiker's Guide to the Galaxy by Douglas Adams concerned the "Answer to the Ultimate Question of Life, the Universe, and Everything," which was 42. Eventually, one character's attempt to divine the Ultimate Question elicited "What do you get if you multiply six by nine?" The mathematical answer is 54, and the story explained the discrepancy. Some readers who were trying to find a deeper meaning in the passage soon noticed a certain veracity when using base-13; 6₁₀ × 9₁₀ = 54₁₀, which can be expressed as 42₁₃ (i.e. the decimal expression 54 is encoded as 42 in base-13). When confronted with this, Adams claimed that it was a mere coincidence, stating that "I may be a sorry case, but I don't write jokes in base 13."

54 is also:

• +54 The code for international direct dial phone calls to Argentina
• The number of the French department Meurthe-et-Moselle
• Year identifier used on motor vehicles registered in the UK between 1 September 2004 and 28 February 2005

See also

• 54 (disambiguation)
  • AD 54
  • 54 BC
  • List of highways numbered 54
• 45 (number) – 54 reversed