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Number

1,213

1,213 is a prime, odd, a calendar year.

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

Historical context — 1213 AD

Year

Year 1213 (MCCXIII) was a common year starting on Tuesday 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
Tuesday
January 1, 1213
Ended on
Tuesday
December 31, 1213
Friday the 13ths
2
2 Friday the 13ths this year.
Decade
1210s
1210–1219
Century
13th century
1201–1300
Millennium
2nd millennium
1001–2000
Years ago
813
813 years before 2026.

In other calendars

Hebrew
4973 / 4974 AM
Rosh Hashanah falls in September/October.
Islamic Hijri
609 / 610 AH
Lunar calendar; year spans differ from Gregorian.
Chinese
Year of the zodiac:Water zodiac:Rooster
Sexagenary cycle position 10 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era
1756 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri
591 / 592 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian
1205 / 1206 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka)
1135 / 1134 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
3,121
Recamán's sequence
a(8,562) = 1,213
Square (n²)
1,471,369
Cube (n³)
1,784,770,597
Divisor count
2
σ(n) — sum of divisors
1,214
φ(n) — Euler's totient
1,212

Primality

1,213 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 1213
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 1,213)
1 × 1213
First multiples
1,213 · 2,426 (double) · 3,639 · 4,852 · 6,065 · 7,278 · 8,491 · 9,704 · 10,917 · 12,130

Sums & aliquot sequence

As a sum of two squares: 22² + 27²
As consecutive integers: 606 + 607

Representations

In words
one thousand two hundred thirteen
Ordinal
1213th
Roman numeral
MCCXIII
Binary
10010111101
Octal
2275
Hexadecimal
0x4BD
Base64
BL0=
One's complement
64,322 (16-bit)
In other bases
ternary (3) 1122221
quaternary (4) 102331
quinary (5) 14323
senary (6) 5341
septenary (7) 3352
nonary (9) 1587
undecimal (11) a03
duodecimal (12) 851
tridecimal (13) 724
tetradecimal (14) 629
pentadecimal (15) 55d

Historical numeral systems

Babylonian (base 60)
𒌋𒌋 𒌋𒁹𒁹𒁹
Egyptian hieroglyphic
𓆼𓍢𓍢𓎆𓏺𓏺𓏺
Greek (Milesian)
͵ασιγʹ
Mayan (base 20)
𝋣·𝋠·𝋭
Chinese
一千二百一十三
Chinese (financial)
壹仟貳佰壹拾參
In other modern scripts
Eastern Arabic ١٢١٣ Devanagari १२१३ Bengali ১২১৩ Tamil ௧௨௧௩ Thai ๑๒๑๓ Tibetan ༡༢༡༣ Khmer ១២១៣ Lao ໑໒໑໓ Burmese ၁၂၁၃

Digit at this position in famous constants

π — Pi (π)
Digit 1,213 = 3
e — Euler's number (e)
Digit 1,213 = 6
φ — Golden ratio (φ)
Digit 1,213 = 1
√2 — Pythagoras's (√2)
Digit 1,213 = 9
ln 2 — Natural log of 2
Digit 1,213 = 7
γ — Euler-Mascheroni (γ)
Digit 1,213 = 6

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 1,201 (gap of 12)
  • Next prime: 1,217 (gap of 4)

Pair status: cousin with 1217.

Unicode codepoint
ҽ
Cyrillic Small Letter Abkhasian Che
U+04BD
Lowercase letter (Ll)

UTF-8 encoding: D2 BD (2 bytes).

Hex color
#0004BD
RGB(0, 4, 189)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.4.189.

Address
0.0.4.189
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.4.189

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

Position in π

The digit sequence 1213 first appears in π at position 47,501 of the decimal expansion (the 47,501ordinal-suffix:st 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.