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Number

1,321

1,321 is a prime, odd, a calendar year.

Arithmetic Number Deficient Number Emirp Odious Number Pernicious Number Prime Pythagorean Prime Recamán's Sequence Sexy Prime Squarefree Twin Prime Year

Historical context — 1321 AD

Calendar year

Year 1321 (MCCCXXI) was a common year starting on Thursday 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
Wednesday
January 1, 1321
Ended on
Wednesday
December 31, 1321
Friday the 13ths
1
One Friday the 13th this year.
Decade
1320s
1320–1329
Century
14th century
1301–1400
Millennium
2nd millennium
1001–2000
Years ago
705
705 years before 2026.

In other calendars

Hebrew
5081 / 5082 AM
Rosh Hashanah falls in September/October.
Islamic Hijri
720 / 721 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
1864 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri
699 / 700 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian
1313 / 1314 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka)
1243 / 1242 Saka
Indian national calendar; year starts in March.

Properties

Parity
Odd
Digit count
4
Digit sum
7
Digit product
6
Digital root
7
Palindrome
No
Bit width
11 bits
Reversed
1,231
Recamán's sequence
a(4,121) = 1,321
Square (n²)
1,745,041
Cube (n³)
2,305,199,161
Divisor count
2
σ(n) — sum of divisors
1,322
φ(n) — Euler's totient
1,320

Primality

1,321 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 1321
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 1,321)
1 × 1321
First multiples
1,321 · 2,642 (double) · 3,963 · 5,284 · 6,605 · 7,926 · 9,247 · 10,568 · 11,889 · 13,210

Sums & aliquot sequence

As a sum of two squares: 5² + 36²
As consecutive integers: 660 + 661

Representations

In words
one thousand three hundred twenty-one
Ordinal
1321st
Roman numeral
MCCCXXI
Binary
10100101001
Octal
2451
Hexadecimal
0x529
Base64
BSk=
One's complement
64,214 (16-bit)
In other bases
ternary (3) 1210221
quaternary (4) 110221
quinary (5) 20241
senary (6) 10041
septenary (7) 3565
nonary (9) 1727
undecimal (11) aa1
duodecimal (12) 921
tridecimal (13) 7a8
tetradecimal (14) 6a5
pentadecimal (15) 5d1

Historical numeral systems

Babylonian (base 60)
𒌋𒌋𒁹𒁹 𒁹
Egyptian hieroglyphic
𓆼𓍢𓍢𓍢𓎆𓎆𓏺
Greek (Milesian)
͵ατκαʹ
Mayan (base 20)
𝋣·𝋦·𝋡
Chinese
一千三百二十一
Chinese (financial)
壹仟參佰貳拾壹
In other modern scripts
Eastern Arabic ١٣٢١ Devanagari १३२१ Bengali ১৩২১ Tamil ௧௩௨௧ Thai ๑๓๒๑ Tibetan ༡༣༢༡ Khmer ១៣២១ Lao ໑໓໒໑ Burmese ၁၃၂၁

Digit at this position in famous constants

π — Pi (π)
Digit 1,321 = 4
e — Euler's number (e)
Digit 1,321 = 8
φ — Golden ratio (φ)
Digit 1,321 = 5
√2 — Pythagoras's (√2)
Digit 1,321 = 9
ln 2 — Natural log of 2
Digit 1,321 = 6
γ — Euler-Mascheroni (γ)
Digit 1,321 = 5

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 1,319 (gap of 2)
  • Next prime: 1,327 (gap of 6)

Pair status: twin with 1319, sexy with 1327.

Unicode codepoint
ԩ
Cyrillic Small Letter En With Left Hook
U+0529
Lowercase letter (Ll)

UTF-8 encoding: D4 A9 (2 bytes).

Hex color
#000529
RGB(0, 5, 41)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.5.41.

Address
0.0.5.41
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.5.41

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

Position in π

The digit sequence 1321 first appears in π at position 16,563 of the decimal expansion (the 16,563ordinal-suffix:rd 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.