618
618 is a composite number, even, a calendar year.
Historical context — 618 AD
Calendar year
Year 618 (DCXVIII) was a common year starting on Sunday of the Julian calendar.
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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 · English fallback 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
Divisors & multiples
Sums & aliquot sequence
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)
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
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'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.
UTF-8 encoding: C9 AA (2 bytes).
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.
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.