8,081
8,081 is a prime, odd.
8,081 (eight thousand eighty-one) is an odd 4-digit number. It is a prime number — divisible only by 1 and itself. Written other ways, in hexadecimal, 0x1F91.
Interestingness
Properties
Primality
8,081 is prime. It has exactly two divisors: 1 and itself.
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√8,081 = [89; (1, 8, 2, 7, 2, 1, 10, 1, 1, 3, 1, 35, 5, 1, 1, 2, 3, 1, 3, 1, 2, 1, 1, 1, …)]
Period length 59 — the block in parentheses repeats forever.
Representations
- In words
- eight thousand eighty-one
- Ordinal
- 8081st
- Binary
- 1111110010001
- Octal
- 17621
- Hexadecimal
- 0x1F91
- Base64
- H5E=
- One's complement
- 57,454 (16-bit)
- Scientific notation
- 8.081 × 10³
- As a duration
- 8,081 s = 2 hours, 14 minutes, 41 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹 𒌋𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹
- Egyptian hieroglyphic
- 𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺
- Greek (Milesian)
- ͵ηπαʹ
- Mayan (base 20)
- 𝋡·𝋠·𝋤·𝋡
- Chinese
- 八千零八十一
- Chinese (financial)
- 捌仟零捌拾壹
Digit at this position in famous constants
- π — Pi (π)
- Digit 8,081 = 5
- e — Euler's number (e)
- Digit 8,081 = 6
- φ — Golden ratio (φ)
- Digit 8,081 = 7
- √2 — Pythagoras's (√2)
- Digit 8,081 = 7
- ln 2 — Natural log of 2
- Digit 8,081 = 7
- γ — Euler-Mascheroni (γ)
- Digit 8,081 = 3
Also seen as
UTF-8 encoding: E1 BE 91 (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.31.145.
- Address
- 0.0.31.145
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.31.145
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 8,081 Hz is closest to:
- Concert pitch (A4 = 440 Hz): B8 (7902.1 Hz, +39¢)
- Scientific pitch (C4 = 256 Hz): C9 (8192 Hz, -24¢)
- Baroque pitch (A4 = 415 Hz): C9 (7896.3 Hz, +40¢)
The digit sequence 8081 first appears in π at position 10,882 of the decimal expansion (the 10,882ordinal-suffix:nd 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.
- Mayan numerals — Vigesimal dots-and-bars with a shell zero — one of the earliest true zeros.