Number

618

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

618 (six hundred eighteen) is an even 3-digit number. It is a composite number with 8 divisors, and factors as 2 × 3 × 103. Its proper divisors sum to 630, more than the number itself, making it an abundant number. Written other ways, in Roman numerals it is DCXVIII and in binary, 1001101010.

Abundant Number Arithmetic Number Cube-Free Flippable Odious Number Pernicious Number Recamán's Sequence Semiperfect Number Sphenic Number Squarefree Year

Interestingness

★ ★ ★ ★ ☆

7 notable facts · grade B

606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630

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Historical context — 618 AD

Calendar year

Year 618 (DCXVIII) was a common year starting on Sunday of the Julian calendar.

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

Historical context — 618 BC

Calendar year

The year 618 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, 618
Ended on: Thursday
December 31, 618
Friday the 13ths: 3
3 Friday the 13ths this year.
Decade: 610s
610–619
Century: 7th century
601–700
Millennium: 1st millennium
1–1000
Years ago: 1,408
1408 years before 2026.

In other calendars

Hebrew: 4378 / 4379 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Earth zodiac:Tiger
Sexagenary cycle position 15 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 1161 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 610 / 611 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 540 / 539 Saka
Indian national calendar; year starts in March.

Properties

Parity: Even
Digit count: 3
Digit sum: 15
Digit product: 48
Digital root: 6
Palindrome: No
Bit width: 10 bits
Reversed: 816
Flips to (rotate 180°): 819
Recamán's sequence: a(8,904) = 618
Square (n²): 381,924
Cube (n³): 236,029,032
Divisor count: 8
σ(n) — sum of divisors: 1,248
φ(n) — Euler's totient: 204
Sum of prime factors: 108

Primality

Prime factorization: 2 × 3 × 103

Nearest primes: 617 (−1) · 619 (+1)

Divisors & multiples

All divisors (8)

1 · 2 · 3 · 6 · 103 · 206 · 309 (half) · 618

Aliquot sum (sum of proper divisors): 630

Factor pairs (a × b = 618)

1 × 618

2 × 309

3 × 206

6 × 103

First multiples

618 · 1,236 (double) · 1,854 · 2,472 · 3,090 · 3,708 · 4,326 · 4,944 · 5,562 · 6,180

Sums & aliquot sequence

As consecutive integers: 205 + 206 + 207 153 + 154 + 155 + 156 46 + 47 + … + 57

Aliquot sequence: 618 → 630 → 1,242 → 1,638 → 2,730 → 5,334 → 6,954 → 7,926 → 7,938 → 12,753 → 7,267 → 785 → 163 → 1 → 0 — terminates at zero

Continued fraction of √n

√618 = [24; (1, 6, 8, 6, 1, 48)]

Period length 6 — the block in parentheses repeats forever.

Representations

In words: six hundred eighteen
Ordinal: 618th
Roman numeral: DCXVIII
Binary: 1001101010
Octal: 1152
Hexadecimal: 0x26A
Base64: Amo=
One's complement: 64,917 (16-bit)
Scientific notation: 6.18 × 10²
As a duration: 618 s = 10 minutes, 18 seconds

In other bases

ternary (3) 211220

quaternary (4) 21222

quinary (5) 4433

senary (6) 2510

septenary (7) 1542

nonary (9) 756

undecimal (11) 512

duodecimal (12) 436

tridecimal (13) 387

tetradecimal (14) 322

pentadecimal (15) 2b3

As an angle

618° = 1 × 360° + 258°

258° ≈ 4.503 rad

Compass bearing: WSW (west-southwest)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋 𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic: 𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian): χιηʹ
Mayan (base 20): 𝋡·𝋪·𝋲
Chinese: 六百一十八
Chinese (financial): 陸佰壹拾捌

In other modern scripts

Eastern Arabic ٦١٨ Devanagari ६१८ Bengali ৬১৮ Tamil ௬௧௮ Thai ๖๑๘ Tibetan ༦༡༨ Khmer ៦១៨ Lao ໖໑໘ Burmese ၆၁၈

Digit at this position in famous constants

π — Pi (π): Digit 618 = 6
e — Euler's number (e): Digit 618 = 4
φ — Golden ratio (φ): Digit 618 = 3
√2 — Pythagoras's (√2): Digit 618 = 0
ln 2 — Natural log of 2: Digit 618 = 8
γ — Euler-Mascheroni (γ): Digit 618 = 9

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 618, here are decompositions:

5 + 613 = 618
11 + 607 = 618
17 + 601 = 618
19 + 599 = 618
31 + 587 = 618
41 + 577 = 618
47 + 571 = 618
61 + 557 = 618

Showing the first eight; more decompositions exist.

Unicode codepoint

Latin Letter Small Capital I

U+026A

Lowercase letter (Ll)

UTF-8 encoding: C9 AA (2 bytes).

Lookup U+026A on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#00026A

RGB(0, 2, 106)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.2.106.

Address: 0.0.2.106
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.2.106

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

NANP area code 618

The number 618 is an active NANP area code (North American Numbering Plan).

Primary area: Southern Illinois
Region: Illinois
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 618 ↗

Musical pitch

Heard as a frequency, 618 Hz is closest to:

Concert pitch (A4 = 440 Hz): D♯5 (622.3 Hz, -12¢)
Scientific pitch (C4 = 256 Hz): D♯5 (608.9 Hz, +26¢)
Baroque pitch (A4 = 415 Hz): E5 (621.8 Hz, -11¢)