Number

54

54 is a composite number, even, a calendar year.

54 (fifty-four) is an even 2-digit number. It is a composite number with 8 divisors, and factors as 2 × 3³. Its proper divisors sum to 66, more than the number itself, making it an abundant number. Written other ways, in Roman numerals it is LIV and in binary, 110110.

Abundant Number Arithmetic Number Evil Number Harshad / Niven Leyland Number Practical Number Recamán's Sequence Semiperfect Number Year

Interestingness

★ ★ ★ ★ ☆

6 notable facts · grade B

42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66

less more

Historical context — 54 AD

Calendar year

AD 54 (LIV) was a common year starting on Tuesday of the Julian calendar.

Excerpt from Wikipedia (en) ↗ · Licensed CC BY-SA 4.0 Read the full article on Wikipedia →

Historical context — 54 BC

Calendar year

Year 54 BC was a year of the pre-Julian Roman calendar.

Excerpt from Wikipedia (en) ↗ · Licensed CC BY-SA 4.0 Read the full article on Wikipedia →

Year facts

Year type: Common year
Standard 365-day year; not divisible by 4 (or divisible by 100 but not 400).
Days in year: 365
ISO weeks: 53
Long year: contains 53 ISO weeks.
Started on: Thursday
January 1, 54
Ended on: Thursday
December 31, 54
Friday the 13ths: 3
3 Friday the 13ths this year.
Decade: 50s
50–59
Century: 1st century
1–100
Millennium: 1st millennium
1–1000
Years ago: 1,972
1972 years before 2026.

In other calendars

Hebrew: 3814 / 3815 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Wood zodiac:Tiger
Sexagenary cycle position 51 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 597 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 46 / 47 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): -24 / -25 Saka
Indian national calendar; year starts in March.

Properties

Parity: Even
Digit count: 2
Digit sum: 9
Digit product: 20
Digital root: 9
Palindrome: No
Bit width: 6 bits
Reversed: 45
Recamán's sequence: a(208) = 54
Square (n²): 2,916
Cube (n³): 157,464
Divisor count: 8
σ(n) — sum of divisors: 120
φ(n) — Euler's totient: 18
Sum of prime factors: 11

Primality

Prime factorization: 2 × 3 ³

Nearest primes: 53 (−1) · 59 (+5)

Divisors & multiples

All divisors (8)

1 · 2 · 3 · 6 · 9 · 18 · 27 (half) · 54

Aliquot sum (sum of proper divisors): 66

Factor pairs (a × b = 54)

1 × 54

2 × 27

3 × 18

6 × 9

First multiples

54 · 108 (double) · 162 · 216 · 270 · 324 · 378 · 432 · 486 · 540

Sums & aliquot sequence

As a sum of two cubes: 3³ + 3³

As consecutive integers: 17 + 18 + 19 12 + 13 + 14 + 15 2 + 3 + … + 10

Aliquot sequence: 54 → 66 → 78 → 90 → 144 → 259 → 45 → 33 → 15 → 9 → 4 → 3 → 1 → 0 — terminates at zero

Continued fraction of √n

√54 = [7; (2, 1, 6, 1, 2, 14)]

Period length 6 — the block in parentheses repeats forever.

Representations

In words: fifty-four
Ordinal: 54th
Roman numeral: LIV
Binary: 110110
Octal: 66
Hexadecimal: 0x36
Base64: Ng==
One's complement: 201 (8-bit)
Scientific notation: 5.4 × 10¹

In other bases

ternary (3) 2000

quaternary (4) 312

quinary (5) 204

senary (6) 130

septenary (7) 105

nonary (9) 60

undecimal (11) 4a

duodecimal (12) 46

tridecimal (13) 42

tetradecimal (14) 3c

pentadecimal (15) 39

As an angle

54°

54° ≈ 0.942 rad

Compass bearing: NE (northeast)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹
Egyptian hieroglyphic: 𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺
Greek (Milesian): νδʹ
Mayan (base 20): 𝋢·𝋮
Chinese: 五十四
Chinese (financial): 伍拾肆

In other modern scripts

Eastern Arabic ٥٤ Devanagari ५४ Bengali ৫৪ Tamil ௫௪ Thai ๕๔ Tibetan ༥༤ Khmer ៥៤ Lao ໕໔ Burmese ၅၄

Digit at this position in famous constants

π — Pi (π): Digit 54 = 2
e — Euler's number (e): Digit 54 = 7
φ — Golden ratio (φ): Digit 54 = 6
√2 — Pythagoras's (√2): Digit 54 = 7
ln 2 — Natural log of 2: Digit 54 = 5
γ — Euler-Mascheroni (γ): Digit 54 = 9

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 54, here are decompositions:

7 + 47 = 54
11 + 43 = 54
13 + 41 = 54
17 + 37 = 54
23 + 31 = 54

ASCII character

As an ASCII codepoint, 54 is 6. Printable ASCII character 6.

Hex color

#000036

RGB(0, 0, 54)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.54.

Address: 0.0.0.54
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.0.54

Unspecified address (0.0.0.0/8) — "this network" placeholder.

Musical pitch

Heard as a frequency, 54 Hz is closest to:

Concert pitch (A4 = 440 Hz): A1 (55 Hz, -32¢)
Scientific pitch (C4 = 256 Hz): A1 (53.8 Hz, +6¢)
Baroque pitch (A4 = 415 Hz): A♯1 (55 Hz, -30¢)

(very low — many laptop and phone speakers can't reproduce it)

As a MIDI note number, 54 is F♯3 (185 Hz at concert pitch).

Atomic number

On the periodic table, atomic number 54 is Xenon (Xe) — period 5.

Xenon on Wikipedia ↗