Number

216

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

Abundant Number Evil Number Harshad / Niven Perfect Cube Powerful Number Practical Number Recamán's Sequence Semiperfect Number Year Zuckerman Number

Historical context — 216 AD

Calendar year

Year 216 (CCXVI) was a leap year starting on Monday of the Julian calendar.

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

Notable events — 216 BC

Aug 2 Hannibal annihilates a Roman army at Cannae.

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

Year facts

Year type: Leap year
Divisible by 4 and not by 100; February has 29 days.
Days in year: 366
ISO weeks: 52
Started on: Monday
January 1, 216
Ended on: Tuesday
December 31, 216
Friday the 13ths: 2
2 Friday the 13ths this year.
Decade: 210s
210–219
Century: 3rd century
201–300
Millennium: 1st millennium
1–1000
Years ago: 1,810
1810 years before 2026.

In other calendars

Hebrew: 3976 / 3977 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Fire zodiac:Monkey
Sexagenary cycle position 33 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 759 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 208 / 209 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 138 / 137 Saka
Indian national calendar; year starts in March.

Cultural significance

Pythagorean sacred

6³ — the "Platonic number" mentioned by Plato in the Republic.

Smallest cube that is also a sum of three cubes (3³ + 4³ + 5³ = 216 = 6³).

Sourced from Wikipedia (Numerology, Chinese numerology, Gematria, and per-culture articles).

Properties

Parity: Even
Digit count: 3
Digit sum: 9
Digit product: 12
Digital root: 9
Palindrome: No
Bit width: 8 bits
Reversed: 612
Recamán's sequence: a(2,600) = 216
Square (n²): 46,656
Cube (n³): 10,077,696
Cube root (∛n): 6
Divisor count: 16
σ(n) — sum of divisors: 600
φ(n) — Euler's totient: 72
Sum of prime factors: 15

Primality

Prime factorization: 2 ³ × 3 ³

Nearest primes: 211 (−5) · 223 (+7)

Divisors & multiples

All divisors (16)

1 · 2 · 3 · 4 · 6 · 8 · 9 · 12 · 18 · 24 · 27 · 36 · 54 · 72 · 108 (half) · 216

Aliquot sum (sum of proper divisors): 384

Factor pairs (a × b = 216)

1 × 216

2 × 108

3 × 72

4 × 54

6 × 36

8 × 27

9 × 24

12 × 18

First multiples

216 · 432 (double) · 648 · 864 · 1,080 · 1,296 · 1,512 · 1,728 · 1,944 · 2,160

Sums & aliquot sequence

As consecutive integers: 71 + 72 + 73 20 + 21 + … + 28 6 + 7 + … + 21

Aliquot sequence: 216 → 384 → 636 → 876 → 1,196 → 1,156 → 993 → 335 → 73 → 1 → 0 — terminates at zero

Representations

In words: two hundred sixteen
Ordinal: 216th
Roman numeral: CCXVI
Binary: 11011000
Octal: 330
Hexadecimal: 0xD8
Base64: 2A==
One's complement: 39 (8-bit)

In other bases

ternary (3) 22000

quaternary (4) 3120

quinary (5) 1331

senary (6) 1000

septenary (7) 426

nonary (9) 260

undecimal (11) 187

duodecimal (12) 160

tridecimal (13) 138

tetradecimal (14) 116

pentadecimal (15) e6

Historical numeral systems

Babylonian (base 60): 𒁹𒁹𒁹 𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic: 𓍢𓍢𓎆𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian): σιϛʹ
Mayan (base 20): 𝋪·𝋰
Chinese: 二百一十六
Chinese (financial): 貳佰壹拾陸

In other modern scripts

Eastern Arabic ٢١٦ Devanagari २१६ Bengali ২১৬ Tamil ௨௧௬ Thai ๒๑๖ Tibetan ༢༡༦ Khmer ២១៦ Lao ໒໑໖ Burmese ၂၁၆

Digit at this position in famous constants

π — Pi (π): Digit 216 = 3
e — Euler's number (e): Digit 216 = 0
φ — Golden ratio (φ): Digit 216 = 0
√2 — Pythagoras's (√2): Digit 216 = 7
ln 2 — Natural log of 2: Digit 216 = 3
γ — Euler-Mascheroni (γ): Digit 216 = 6

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 216, here are decompositions:

5 + 211 = 216
17 + 199 = 216
19 + 197 = 216
23 + 193 = 216
37 + 179 = 216
43 + 173 = 216
53 + 163 = 216
59 + 157 = 216

Showing the first eight; more decompositions exist.

Unicode codepoint

Latin Capital Letter O With Stroke

U+00D8

Uppercase letter (Lu)

UTF-8 encoding: C3 98 (2 bytes).

Lookup U+00D8 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#0000D8

RGB(0, 0, 216)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.216.

Address: 0.0.0.216
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.0.216

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

NANP area code 216

The number 216 is an active NANP area code (North American Numbering Plan).

Primary area: Cleveland
Region: Ohio
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 216 ↗