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Number

131

131 is a prime, odd, a calendar year.

Arithmetic Number Chen Prime Cousin Prime Deficient Number Odious Number Palindrome Pernicious Number Prime Recamán's Sequence Sexy Prime Sophie Germain Prime Squarefree Year

Historical context — 131 AD

Calendar year

Year 131 (CXXXI) was a common year starting on Sunday of the Julian calendar.

Excerpt from Wikipedia (en) ↗ · Licensed CC BY-SA 4.0 · English fallback Read the full article on Wikipedia →

Historical context — 131 BC

Calendar year

Year 131 BC was a year of the pre-Julian Roman calendar.

Excerpt from Wikipedia (en) ↗ · Licensed CC BY-SA 4.0 · English fallback Read the full article on Wikipedia →

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: Monday
January 1, 131
Ended on: Monday
December 31, 131
Friday the 13ths: 2
2 Friday the 13ths this year.
Decade: 130s
130–139
Century: 2nd century
101–200
Millennium: 1st millennium
1–1000
Years ago: 1,895
1895 years before 2026.

In other calendars

Hebrew: 3891 / 3892 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Metal zodiac:Goat
Sexagenary cycle position 8 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 674 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 123 / 124 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 53 / 52 Saka
Indian national calendar; year starts in March.

Properties

Parity: Odd
Digit count: 3
Digit sum: 5
Digit product: 3
Digital root: 5
Palindrome: Yes
Bit width: 8 bits
Recamán's sequence: a(138) = 131
Square (n²): 17,161
Cube (n³): 2,248,091
Divisor count: 2
σ(n) — sum of divisors: 132
φ(n) — Euler's totient: 130

Primality

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

Divisors & multiples

All divisors (2)

1 · 131

Aliquot sum (sum of proper divisors): 1

Factor pairs (a × b = 131)

1 × 131

First multiples

131 · 262 (double) · 393 · 524 · 655 · 786 · 917 · 1,048 · 1,179 · 1,310

Sums & aliquot sequence

As consecutive integers: 65 + 66

Representations

In words: one hundred thirty-one
Ordinal: 131st
Roman numeral: CXXXI
Binary: 10000011
Octal: 203
Hexadecimal: 0x83
Base64: gw==
One's complement: 124 (8-bit)

In other bases

ternary (3) 11212

quaternary (4) 2003

quinary (5) 1011

senary (6) 335

septenary (7) 245

nonary (9) 155

undecimal (11) 10a

duodecimal (12) ab

tridecimal (13) a1

tetradecimal (14) 95

pentadecimal (15) 8b

Historical numeral systems

Babylonian (base 60): 𒁹𒁹 𒌋𒁹
Egyptian hieroglyphic: 𓍢𓎆𓎆𓎆𓏺
Greek (Milesian): ρλαʹ
Mayan (base 20): 𝋦·𝋫
Chinese: 一百三十一
Chinese (financial): 壹佰參拾壹

In other modern scripts

Eastern Arabic ١٣١ Devanagari १३१ Bengali ১৩১ Tamil ௧௩௧ Thai ๑๓๑ Tibetan ༡༣༡ Khmer ១៣១ Lao ໑໓໑ Burmese ၁၃၁

Digit at this position in famous constants

π — Pi (π): Digit 131 = 5
e — Euler's number (e): Digit 131 = 6
φ — Golden ratio (φ): Digit 131 = 2
√2 — Pythagoras's (√2): Digit 131 = 8
ln 2 — Natural log of 2: Digit 131 = 7
γ — Euler-Mascheroni (γ): Digit 131 = 4

Also seen as

Prime neighborhood

Adjacent primes:

Previous prime: 127 (gap of 4)
Next prime: 137 (gap of 6)

Pair status: cousin with 127, sexy with 137.

Unicode codepoint

No Break Here

U+0083

Control character (Cc)

UTF-8 encoding: C2 83 (2 bytes).

Lookup U+0083 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#000083

RGB(0, 0, 131)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.131.

Address: 0.0.0.131
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.0.131

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