212
212 is a composite number, even, a calendar year.
212 (two hundred twelve) is an even 3-digit number. It is a composite number with 6 divisors, and factors as 2² × 53. Its digits read the same forwards and backwards, so it is a palindromic number. Written other ways, in Roman numerals it is CCXII and in binary, 11010100.
Interestingness
Historical context — 212 AD
Calendar year
Year 212 (CCXII) was a leap year starting on Wednesday of the Julian calendar.
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Historical context — 212 BC
Calendar year
Year 212 BC was a year of the pre-Julian Roman 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
-
53
Long year: contains 53 ISO weeks.
- Started on
-
Wednesday
January 1, 212
- Ended on
-
Thursday
December 31, 212
- 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
-
1,814
1814 years before 2026.
In other calendars
- Hebrew
-
3972 / 3973 AM
Rosh Hashanah falls in September/October.
- Chinese
-
Year of the zodiac:Water zodiac:Dragon
Sexagenary cycle position 29 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
755 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Ethiopian
-
204 / 205 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
134 / 133 Saka
Indian national calendar; year starts in March.
Properties
Primality
Prime factorization: 2 2 × 53
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√212 = [14; (1, 1, 3, 1, 1, 1, 6, 1, 1, 1, 3, 1, 1, 28)]
Period length 14 — the block in parentheses repeats forever.
Representations
- In words
- two hundred twelve
- Ordinal
- 212th
- Roman numeral
- CCXII
- Binary
- 11010100
- Octal
- 324
- Hexadecimal
- 0xD4
- Base64
- 1A==
- One's complement
- 43 (8-bit)
- Scientific notation
- 2.12 × 10²
- As a duration
- 212 s = 3 minutes, 32 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹 𒌋𒌋𒌋𒁹𒁹
- Egyptian hieroglyphic
- 𓍢𓍢𓎆𓏺𓏺
- Greek (Milesian)
- σιβʹ
- Mayan (base 20)
- 𝋪·𝋬
- Chinese
- 二百一十二
- Chinese (financial)
- 貳佰壹拾貳
Digit at this position in famous constants
- π — Pi (π)
- Digit 212 = 6
- e — Euler's number (e)
- Digit 212 = 9
- φ — Golden ratio (φ)
- Digit 212 = 8
- √2 — Pythagoras's (√2)
- Digit 212 = 6
- ln 2 — Natural log of 2
- Digit 212 = 9
- γ — Euler-Mascheroni (γ)
- Digit 212 = 9
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 212, here are decompositions:
- 13 + 199 = 212
- 19 + 193 = 212
- 31 + 181 = 212
- 61 + 151 = 212
- 73 + 139 = 212
- 103 + 109 = 212
UTF-8 encoding: C3 94 (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.212.
- Address
- 0.0.0.212
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.0.212
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The number 212 is an active NANP area code (North American Numbering Plan).
- Primary area
- Manhattan
- Region
- New York
- 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.
Heard as a frequency, 212 Hz is closest to:
- Concert pitch (A4 = 440 Hz): G♯3 (207.7 Hz, +36¢)
- Scientific pitch (C4 = 256 Hz): A3 (215.3 Hz, -26¢)
- Baroque pitch (A4 = 415 Hz): A3 (207.5 Hz, +37¢)
212 °F is the boiling point of water (100 °C).
Related reading
- Mayan numerals — Vigesimal dots-and-bars with a shell zero — one of the earliest true zeros.