1,961
1,961 is a composite number, odd, a calendar year.
1,961 (one thousand nine hundred sixty-one) is an odd 4-digit number. It is a composite number with 4 divisors, and factors as 37 × 53. Written other ways, in Roman numerals it is MCMLXI and in binary, 11110101001.
Interestingness
Notable events — 1961 AD
- Jan 20 John F. Kennedy is inaugurated as the 35th US president.
- Apr 12 Yuri Gagarin becomes the first human in space aboard Vostok 1.
- Apr 17 The CIA-backed Bay of Pigs invasion of Cuba fails.
- May 5 Alan Shepard becomes the first American in space.
- Aug 13 East Germany begins building the Berlin Wall.
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
-
Sunday
January 1, 1961
- Ended on
-
Sunday
December 31, 1961
- Friday the 13ths
-
2
2 Friday the 13ths this year.
- Easter Sunday
-
April 2
Sunday, April 2, 1961
- Decade
-
1960s
1960–1969
- Century
-
20th century
1901–2000
- Millennium
-
2nd millennium
1001–2000
- Years ago
-
65
65 years before 2026.
In other calendars
- Hebrew
-
5721 / 5722 AM
Rosh Hashanah falls in September/October.
- Islamic Hijri
-
1380 / 1381 AH
Lunar calendar; year spans differ from Gregorian.
- Chinese
-
Year of the zodiac:Metal zodiac:Ox
Sexagenary cycle position 38 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
2504 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Persian Solar Hijri
-
1339 / 1340 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
- Ethiopian
-
1953 / 1954 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
1883 / 1882 Saka
Indian national calendar; year starts in March.
- Japanese
-
Shōwa 36
Reign-era counting from the start of each emperor's reign.
Properties
Primality
Prime factorization: 37 × 53
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√1,961 = [44; (3, 1, 1, 7, 2, 12, 5, 2, 5, 12, 2, 7, 1, 1, 3, 88)]
Period length 16 — the block in parentheses repeats forever.
Representations
- In words
- one thousand nine hundred sixty-one
- Ordinal
- 1961st
- Roman numeral
- MCMLXI
- Binary
- 11110101001
- Octal
- 3651
- Hexadecimal
- 0x7A9
- Base64
- B6k=
- One's complement
- 63,574 (16-bit)
- Scientific notation
- 1.961 × 10³
- As a duration
- 1,961 s = 32 minutes, 41 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒌋𒁹𒁹 𒌋𒌋𒌋𒌋𒁹
- Egyptian hieroglyphic
- 𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓏺
- Greek (Milesian)
- ͵αϡξαʹ
- Mayan (base 20)
- 𝋤·𝋲·𝋡
- Chinese
- 一千九百六十一
- Chinese (financial)
- 壹仟玖佰陸拾壹
Digit at this position in famous constants
- π — Pi (π)
- Digit 1,961 = 5
- e — Euler's number (e)
- Digit 1,961 = 7
- φ — Golden ratio (φ)
- Digit 1,961 = 0
- √2 — Pythagoras's (√2)
- Digit 1,961 = 5
- ln 2 — Natural log of 2
- Digit 1,961 = 7
- γ — Euler-Mascheroni (γ)
- Digit 1,961 = 5
Also seen as
UTF-8 encoding: DE A9 (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.7.169.
- Address
- 0.0.7.169
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.7.169
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 1,961 Hz is closest to:
- Concert pitch (A4 = 440 Hz): B6 (1975.5 Hz, -13¢)
- Scientific pitch (C4 = 256 Hz): B6 (1933.1 Hz, +25¢)
- Baroque pitch (A4 = 415 Hz): C7 (1974.1 Hz, -12¢)
The digit sequence 1961 first appears in π at position 2,997 of the decimal expansion (the 2,997ordinal-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
- Mayan numerals — Vigesimal dots-and-bars with a shell zero — one of the earliest true zeros.