Number

1,618

1,618 is a composite number, even, a calendar year.

1,618 (one thousand six hundred eighteen) is an even 4-digit number. It is a composite number with 4 divisors, and factors as 2 × 809. Written other ways, in Roman numerals it is MDCXVIII and in binary, 11001010010.

Cube-Free Deficient Number Flippable Odious Number Pernicious Number Recamán's Sequence Semiprime Squarefree Year

Interestingness

★ ★ ★ ☆ ☆

5 notable facts · grade C

1,606 1,607 1,608 1,609 1,610 1,611 1,612 1,613 1,614 1,615 1,616 1,617 1,618 1,619 1,620 1,621 1,622 1,623 1,624 1,625 1,626 1,627 1,628 1,629 1,630

less more

Notable events — 1618 AD

May 23 The Defenestration of Prague sparks the Thirty Years' War.
Oct 29 Sir Walter Raleigh is executed in England.
Sep 14 Kepler publishes the third of his laws of planetary motion.

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: Monday
January 1, 1618
Ended on: Monday
December 31, 1618
Friday the 13ths: 2
2 Friday the 13ths this year.
Easter Sunday: April 15
Sunday, April 15, 1618
Decade: 1610s
1610–1619
Century: 17th century
1601–1700
Millennium: 2nd millennium
1001–2000
Years ago: 408
408 years before 2026.

In other calendars

Hebrew: 5378 / 5379 AM
Rosh Hashanah falls in September/October.
Islamic Hijri: 1027 / 1028 AH
Lunar calendar; year spans differ from Gregorian.
Chinese: Year of the zodiac:Earth zodiac:Horse
Sexagenary cycle position 55 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 2161 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri: 996 / 997 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian: 1610 / 1611 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 1540 / 1539 Saka
Indian national calendar; year starts in March.

Properties

Parity: Even
Digit count: 4
Digit sum: 16
Digit product: 48
Digital root: 7
Palindrome: No
Bit width: 11 bits
Reversed: 8,161
Flips to (rotate 180°): 8,191
Recamán's sequence: a(716) = 1,618
Square (n²): 2,617,924
Cube (n³): 4,235,801,032
Divisor count: 4
σ(n) — sum of divisors: 2,430
φ(n) — Euler's totient: 808
Sum of prime factors: 811

Primality

Prime factorization: 2 × 809

Nearest primes: 1,613 (−5) · 1,619 (+1)

Divisors & multiples

All divisors (4)

1 · 2 · 809 (half) · 1618

Aliquot sum (sum of proper divisors): 812

Factor pairs (a × b = 1,618)

1 × 1618

2 × 809

First multiples

1,618 · 3,236 (double) · 4,854 · 6,472 · 8,090 · 9,708 · 11,326 · 12,944 · 14,562 · 16,180

Sums & aliquot sequence

As a sum of two squares: 23² + 33²

As consecutive integers: 403 + 404 + 405 + 406

Aliquot sequence: 1,618 → 812 → 868 → 924 → 1,764 → 3,423 → 1,825 → 469 → 75 → 49 → 8 → 7 → 1 → 0 — terminates at zero

Continued fraction of √n

√1,618 = [40; (4, 2, 5, 3, 3, 5, 2, 4, 80)]

Period length 9 — the block in parentheses repeats forever.

Representations

In words: one thousand six hundred eighteen
Ordinal: 1618th
Roman numeral: MDCXVIII
Binary: 11001010010
Octal: 3122
Hexadecimal: 0x652
Base64: BlI=
One's complement: 63,917 (16-bit)
Scientific notation: 1.618 × 10³
As a duration: 1,618 s = 26 minutes, 58 seconds

In other bases

ternary (3) 2012221

quaternary (4) 121102

quinary (5) 22433

senary (6) 11254

septenary (7) 4501

nonary (9) 2187

undecimal (11) 1241

duodecimal (12) b2a

tridecimal (13) 976

tetradecimal (14) 838

pentadecimal (15) 72d

Palindromic in base 14

As an angle

1,618° = 4 × 360° + 178°

178° ≈ 3.107 rad

Compass bearing: S (south)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic: 𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian): ͵αχιηʹ
Mayan (base 20): 𝋤·𝋠·𝋲
Chinese: 一千六百一十八
Chinese (financial): 壹仟陸佰壹拾捌

In other modern scripts

Eastern Arabic ١٦١٨ Devanagari १६१८ Bengali ১৬১৮ Tamil ௧௬௧௮ Thai ๑๖๑๘ Tibetan ༡༦༡༨ Khmer ១៦១៨ Lao ໑໖໑໘ Burmese ၁၆၁၈

Digit at this position in famous constants

π — Pi (π): Digit 1,618 = 9
e — Euler's number (e): Digit 1,618 = 5
φ — Golden ratio (φ): Digit 1,618 = 2
√2 — Pythagoras's (√2): Digit 1,618 = 2
ln 2 — Natural log of 2: Digit 1,618 = 2
γ — Euler-Mascheroni (γ): Digit 1,618 = 4

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 1618, here are decompositions:

5 + 1613 = 1618
11 + 1607 = 1618
17 + 1601 = 1618
47 + 1571 = 1618
59 + 1559 = 1618
107 + 1511 = 1618
131 + 1487 = 1618
137 + 1481 = 1618

Showing the first eight; more decompositions exist.

Unicode codepoint

Arabic Sukun

U+0652

Non-spacing mark (Mn)

UTF-8 encoding: D9 92 (2 bytes).

Lookup U+0652 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#000652

RGB(0, 6, 82)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.6.82.

Address: 0.0.6.82
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.6.82

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

Musical pitch

Heard as a frequency, 1,618 Hz is closest to:

Concert pitch (A4 = 440 Hz): G♯6 (1661.2 Hz, -46¢ — about midway to G6)
Scientific pitch (C4 = 256 Hz): G♯6 (1625.5 Hz, -8¢)
Baroque pitch (A4 = 415 Hz): A6 (1660 Hz, -44¢)

Position in π

The digit sequence 1618 first appears in π at position 6,004 of the decimal expansion (the 6,004ordinal-suffix:th digit after the integer 3).

Search range: the first 1,000,000 fractional digits of π. Any 6-digit-or-shorter string is virtually guaranteed to appear in there — the more interesting signal is the position.

Look up 1618 on Pi Search ↗