Number

551

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

Arithmetic Number Deficient Number Odious Number Pernicious Number Recamán's Sequence Semiprime Squarefree Year

Historical context — 551 AD

Calendar year

Year 551 (DLI) was a common year starting on Sunday of the Julian calendar.

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

Notable events — 551 BC

Undated Traditional birth year of Confucius.

Events compiled from Wikipedia ↗ · Licensed CC BY-SA 4.0

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: Friday
January 1, 551
Ended on: Friday
December 31, 551
Friday the 13ths: 1
One Friday the 13th this year.
Decade: 550s
550–559
Century: 6th century
501–600
Millennium: 1st millennium
1–1000
Years ago: 1,475
1475 years before 2026.

In other calendars

Hebrew: 4311 / 4312 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Metal zodiac:Goat
Sexagenary cycle position 8 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 1094 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 543 / 544 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 473 / 472 Saka
Indian national calendar; year starts in March.

Properties

Parity: Odd
Digit count: 3
Digit sum: 11
Digit product: 25
Digital root: 2
Palindrome: No
Bit width: 10 bits
Reversed: 155
Recamán's sequence: a(1,157) = 551
Square (n²): 303,601
Cube (n³): 167,284,151
Divisor count: 4
σ(n) — sum of divisors: 600
φ(n) — Euler's totient: 504
Sum of prime factors: 48

Primality

Prime factorization: 19 × 29

Nearest primes: 547 (−4) · 557 (+6)

Divisors & multiples

All divisors (4)

1 · 19 · 29 · 551

Aliquot sum (sum of proper divisors): 49

Factor pairs (a × b = 551)

1 × 551

19 × 29

First multiples

551 · 1,102 (double) · 1,653 · 2,204 · 2,755 · 3,306 · 3,857 · 4,408 · 4,959 · 5,510

Sums & aliquot sequence

As consecutive integers: 275 + 276 20 + 21 + … + 38 5 + 6 + … + 33

Aliquot sequence: 551 → 49 → 8 → 7 → 1 → 0 — terminates at zero

Representations

In words: five hundred fifty-one
Ordinal: 551st
Roman numeral: DLI
Binary: 1000100111
Octal: 1047
Hexadecimal: 0x227
Base64: Aic=
One's complement: 64,984 (16-bit)

In other bases

ternary (3) 202102

quaternary (4) 20213

quinary (5) 4201

senary (6) 2315

septenary (7) 1415

nonary (9) 672

undecimal (11) 461

duodecimal (12) 39b

tridecimal (13) 335

tetradecimal (14) 2b5

pentadecimal (15) 26b

Historical numeral systems

Babylonian (base 60): 𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒁹
Egyptian hieroglyphic: 𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓏺
Greek (Milesian): φναʹ
Mayan (base 20): 𝋡·𝋧·𝋫
Chinese: 五百五十一
Chinese (financial): 伍佰伍拾壹

In other modern scripts

Eastern Arabic ٥٥١ Devanagari ५५१ Bengali ৫৫১ Tamil ௫௫௧ Thai ๕๕๑ Tibetan ༥༥༡ Khmer ៥៥១ Lao ໕໕໑ Burmese ၅၅၁

Digit at this position in famous constants

π — Pi (π): Digit 551 = 8
e — Euler's number (e): Digit 551 = 5
φ — Golden ratio (φ): Digit 551 = 4
√2 — Pythagoras's (√2): Digit 551 = 0
ln 2 — Natural log of 2: Digit 551 = 1
γ — Euler-Mascheroni (γ): Digit 551 = 2

Also seen as

Unicode codepoint

Latin Small Letter A With Dot Above

U+0227

Lowercase letter (Ll)

UTF-8 encoding: C8 A7 (2 bytes).

Lookup U+0227 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#000227

RGB(0, 2, 39)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.2.39.

Address: 0.0.2.39
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.2.39

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

NANP area code 551

The number 551 is an active NANP area code (North American Numbering Plan).

Primary area: Jersey City / Hackensack
Region: New Jersey
Country: United States

Most NANP area codes have multiple overlays in dense regions; the primary area listed is the historic/largest population center for this code.

Look up area code 551 ↗