2,131
2,131 is a prime, odd.
2,131 (two thousand one hundred thirty-one) is an odd 4-digit number. It is a prime number — divisible only by 1 and itself. Written other ways, in Roman numerals it is MMCXXXI and in binary, 100001010011.
Interestingness
Properties
Primality
2,131 is prime. It has exactly two divisors: 1 and itself.
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√2,131 = [46; (6, 6, 1, 14, 1, 1, 8, 1, 2, 1, 1, 9, 1, 2, 5, 1, 4, 3, 2, 18, 30, 1, 2, 1, …)]
Period length 58 — the block in parentheses repeats forever.
Representations
- In words
- two thousand one hundred thirty-one
- Ordinal
- 2131st
- Roman numeral
- MMCXXXI
- Binary
- 100001010011
- Octal
- 4123
- Hexadecimal
- 0x853
- Base64
- CFM=
- One's complement
- 63,404 (16-bit)
- Scientific notation
- 2.131 × 10³
- As a duration
- 2,131 s = 35 minutes, 31 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒁹
- Egyptian hieroglyphic
- 𓆼𓆼𓍢𓎆𓎆𓎆𓏺
- Greek (Milesian)
- ͵βρλαʹ
- Mayan (base 20)
- 𝋥·𝋦·𝋫
- Chinese
- 二千一百三十一
- Chinese (financial)
- 貳仟壹佰參拾壹
Digit at this position in famous constants
- π — Pi (π)
- Digit 2,131 = 0
- e — Euler's number (e)
- Digit 2,131 = 7
- φ — Golden ratio (φ)
- Digit 2,131 = 7
- √2 — Pythagoras's (√2)
- Digit 2,131 = 1
- ln 2 — Natural log of 2
- Digit 2,131 = 9
- γ — Euler-Mascheroni (γ)
- Digit 2,131 = 0
Also seen as
UTF-8 encoding: E0 A1 93 (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.8.83.
- Address
- 0.0.8.83
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.8.83
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 2,131 Hz is closest to:
- Concert pitch (A4 = 440 Hz): C7 (2093 Hz, +31¢)
- Scientific pitch (C4 = 256 Hz): C♯7 (2169.8 Hz, -31¢)
- Baroque pitch (A4 = 415 Hz): C♯7 (2091.5 Hz, +32¢)
The digit sequence 2131 first appears in π at position 3,901 of the decimal expansion (the 3,901ordinal-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.
Related reading
- Prime numbers — The building blocks of arithmetic: what primes are, why they matter, and how we find them.
- Egyptian hieroglyphic numerals — Seven hieroglyphs for every power of ten, from a single stroke to a million.