Number

57

57 is a composite number, odd, a calendar year.

57 (fifty-seven) is an odd 2-digit number. It is a composite number with 4 divisors, and factors as 3 × 19. Written other ways, in Roman numerals it is LVII and in binary, 111001.

Arithmetic Number Cube-Free Deficient Number Evil Number Leyland Number Recamán's Sequence Semiprime Squarefree Year

Interestingness

★ ★ ★ ★ ☆

6 notable facts · grade B

45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69

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Historical context — 57 AD

Calendar year

AD 57 (LVII) was a common year starting on Saturday of the Julian calendar.

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

Historical context — 57 BC

Calendar year

Year 57 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: 52
Started on: Monday
January 1, 57
Ended on: Monday
December 31, 57
Friday the 13ths: 2
2 Friday the 13ths this year.
Decade: 50s
50–59
Century: 1st century
1–100
Millennium: 1st millennium
1–1000
Years ago: 1,969
1969 years before 2026.

In other calendars

Hebrew: 3817 / 3818 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Fire zodiac:Snake
Sexagenary cycle position 54 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 600 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 49 / 50 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): -21 / -22 Saka
Indian national calendar; year starts in March.

Properties

Parity: Odd
Digit count: 2
Digit sum: 12
Digit product: 35
Digital root: 3
Palindrome: No
Bit width: 6 bits
Reversed: 75
Recamán's sequence: a(202) = 57
Square (n²): 3,249
Cube (n³): 185,193
Divisor count: 4
σ(n) — sum of divisors: 80
φ(n) — Euler's totient: 36
Sum of prime factors: 22

Primality

Prime factorization: 3 × 19

Nearest primes: 53 (−4) · 59 (+2)

Divisors & multiples

All divisors (4)

1 · 3 · 19 · 57

Aliquot sum (sum of proper divisors): 23

Factor pairs (a × b = 57)

1 × 57

3 × 19

First multiples

57 · 114 (double) · 171 · 228 · 285 · 342 · 399 · 456 · 513 · 570

Sums & aliquot sequence

As consecutive integers: 28 + 29 18 + 19 + 20 7 + 8 + 9 + 10 + 11 + 12

Aliquot sequence: 57 → 23 → 1 → 0 — terminates at zero

Continued fraction of √n

√57 = [7; (1, 1, 4, 1, 1, 14)]

Period length 6 — the block in parentheses repeats forever.

Representations

In words: fifty-seven
Ordinal: 57th
Roman numeral: LVII
Binary: 111001
Octal: 71
Hexadecimal: 0x39
Base64: OQ==
One's complement: 198 (8-bit)
Scientific notation: 5.7 × 10¹

In other bases

ternary (3) 2010

quaternary (4) 321

quinary (5) 212

senary (6) 133

septenary (7) 111

nonary (9) 63

undecimal (11) 52

duodecimal (12) 49

tridecimal (13) 45

tetradecimal (14) 41

pentadecimal (15) 3c

Palindromic in base 5, base 7

As an angle

57°

57° ≈ 0.995 rad

Compass bearing: ENE (east-northeast)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic: 𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian): νζʹ
Mayan (base 20): 𝋢·𝋱
Chinese: 五十七
Chinese (financial): 伍拾柒

In other modern scripts

Eastern Arabic ٥٧ Devanagari ५७ Bengali ৫৭ Tamil ௫௭ Thai ๕๗ Tibetan ༥༧ Khmer ៥៧ Lao ໕໗ Burmese ၅၇

Digit at this position in famous constants

π — Pi (π): Digit 57 = 7
e — Euler's number (e): Digit 57 = 6
φ — Golden ratio (φ): Digit 57 = 3
√2 — Pythagoras's (√2): Digit 57 = 7
ln 2 — Natural log of 2: Digit 57 = 2
γ — Euler-Mascheroni (γ): Digit 57 = 0

Also seen as

ASCII character

As an ASCII codepoint, 57 is 9. Printable ASCII character 9.

Hex color

#000039

RGB(0, 0, 57)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.57.

Address: 0.0.0.57
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.0.57

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

US numbered highway

Matches numbered highway designation:

I-57 — Sikeston, MO to Chicago, IL.

Interstate 57 on Wikipedia ↗

Musical pitch

Heard as a frequency, 57 Hz is closest to:

Concert pitch (A4 = 440 Hz): A♯1 (58.3 Hz, -38¢)
Scientific pitch (C4 = 256 Hz): A♯1 (57 Hz, -1¢)
Baroque pitch (A4 = 415 Hz): B1 (58.2 Hz, -37¢)

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

As a MIDI note number, 57 is A3 (220 Hz at concert pitch).

Atomic number

On the periodic table, atomic number 57 is Lanthanum (La) — period 6.

Lanthanum on Wikipedia ↗