1,216
1,216 is a composite number, even, a calendar year.
1,216 (one thousand two hundred sixteen) is an even 4-digit number. It is a composite number with 14 divisors, and factors as 2⁶ × 19. Its proper divisors sum to 1,324, more than the number itself, making it an abundant number. Written other ways, in Roman numerals it is MCCXVI and in binary, 10011000000.
Interestingness
Historical context — 1216 AD
Calendar year
Year 1216 (MCCXVI) was a leap year starting on Friday of the Julian calendar.
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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
-
Friday
January 1, 1216
- Ended on
-
Saturday
December 31, 1216
- Friday the 13ths
-
1
One Friday the 13th this year.
- Decade
-
1210s
1210–1219
- Century
-
13th century
1201–1300
- Millennium
-
2nd millennium
1001–2000
- Years ago
-
810
810 years before 2026.
In other calendars
- Hebrew
-
4976 / 4977 AM
Rosh Hashanah falls in September/October.
- Islamic Hijri
-
612 / 613 AH
Lunar calendar; year spans differ from Gregorian.
- Chinese
-
Year of the zodiac:Fire zodiac:Rat
Sexagenary cycle position 13 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
1759 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Persian Solar Hijri
-
594 / 595 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
- Ethiopian
-
1208 / 1209 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
1138 / 1137 Saka
Indian national calendar; year starts in March.
Properties
Primality
Prime factorization: 2 6 × 19
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√1,216 = [34; (1, 6, 1, 3, 4, 2, 1, 1, 4, 17, 4, 1, 1, 2, 4, 3, 1, 6, 1, 68)]
Period length 20 — the block in parentheses repeats forever.
Representations
- In words
- one thousand two hundred sixteen
- Ordinal
- 1216th
- Roman numeral
- MCCXVI
- Binary
- 10011000000
- Octal
- 2300
- Hexadecimal
- 0x4C0
- Base64
- BMA=
- One's complement
- 64,319 (16-bit)
- Scientific notation
- 1.216 × 10³
- As a duration
- 1,216 s = 20 minutes, 16 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋 𒌋𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓆼𓍢𓍢𓎆𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ͵ασιϛʹ
- Mayan (base 20)
- 𝋣·𝋠·𝋰
- Chinese
- 一千二百一十六
- Chinese (financial)
- 壹仟貳佰壹拾陸
Digit at this position in famous constants
- π — Pi (π)
- Digit 1,216 = 7
- e — Euler's number (e)
- Digit 1,216 = 0
- φ — Golden ratio (φ)
- Digit 1,216 = 0
- √2 — Pythagoras's (√2)
- Digit 1,216 = 5
- ln 2 — Natural log of 2
- Digit 1,216 = 4
- γ — Euler-Mascheroni (γ)
- Digit 1,216 = 9
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 1216, here are decompositions:
- 3 + 1213 = 1216
- 23 + 1193 = 1216
- 29 + 1187 = 1216
- 53 + 1163 = 1216
- 107 + 1109 = 1216
- 113 + 1103 = 1216
- 167 + 1049 = 1216
- 197 + 1019 = 1216
Showing the first eight; more decompositions exist.
UTF-8 encoding: D3 80 (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.4.192.
- Address
- 0.0.4.192
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.4.192
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 1,216 Hz is closest to:
- Concert pitch (A4 = 440 Hz): D♯6 (1244.5 Hz, -40¢)
- Scientific pitch (C4 = 256 Hz): D♯6 (1217.7 Hz, -2¢)
- Baroque pitch (A4 = 415 Hz): E6 (1243.6 Hz, -39¢)
The digit sequence 1216 first appears in π at position 6,985 of the decimal expansion (the 6,985ordinal-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.
Related reading
- Egyptian hieroglyphic numerals — Seven hieroglyphs for every power of ten, from a single stroke to a million.