1,261
1,261 is a composite number, odd, a calendar year.
Historical context — 1261 AD
Calendar year
Year 1261 (MCCLXI) was a common year starting on Saturday of the Julian calendar.
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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
-
Saturday
January 1, 1261
- Ended on
-
Saturday
December 31, 1261
- Friday the 13ths
-
1
One Friday the 13th this year.
- Decade
-
1260s
1260–1269
- Century
-
13th century
1201–1300
- Millennium
-
2nd millennium
1001–2000
- Years ago
-
765
765 years before 2026.
In other calendars
- Hebrew
-
5021 / 5022 AM
Rosh Hashanah falls in September/October.
- Islamic Hijri
-
659 / 660 AH
Lunar calendar; year spans differ from Gregorian.
- Chinese
-
Year of the zodiac:Metal zodiac:Rooster
Sexagenary cycle position 58 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
1804 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Persian Solar Hijri
-
639 / 640 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
- Ethiopian
-
1253 / 1254 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
1183 / 1182 Saka
Indian national calendar; year starts in March.
Properties
Primality
Prime factorization: 13 × 97
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- one thousand two hundred sixty-one
- Ordinal
- 1261st
- Roman numeral
- MCCLXI
- Binary
- 10011101101
- Octal
- 2355
- Hexadecimal
- 0x4ED
- Base64
- BO0=
- One's complement
- 64,274 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒁹 𒁹
- Egyptian hieroglyphic
- 𓆼𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓏺
- Greek (Milesian)
- ͵ασξαʹ
- Mayan (base 20)
- 𝋣·𝋣·𝋡
- Chinese
- 一千二百六十一
- Chinese (financial)
- 壹仟貳佰陸拾壹
Digit at this position in famous constants
- π — Pi (π)
- Digit 1,261 = 9
- e — Euler's number (e)
- Digit 1,261 = 2
- φ — Golden ratio (φ)
- Digit 1,261 = 0
- √2 — Pythagoras's (√2)
- Digit 1,261 = 4
- ln 2 — Natural log of 2
- Digit 1,261 = 5
- γ — Euler-Mascheroni (γ)
- Digit 1,261 = 0
Also seen as
UTF-8 encoding: D3 AD (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.4.237.
- Address
- 0.0.4.237
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.4.237
Unspecified address (0.0.0.0/8) — "this network" placeholder.
This passes the ABA routing number checksum and matches the Federal Reserve numbering scheme.
Banks operate many routing numbers per state and division; an unmatched checksum-valid number can still be a real RTN at a smaller institution.
The digit sequence 1261 first appears in π at position 26,714 of the decimal expansion (the 26,714ordinal-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.