2,129
2,129 is a prime, odd.
2,129 (two thousand one hundred twenty-nine) 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 MMCXXIX and in binary, 100001010001.
Interestingness
Properties
- Parity
- Odd
- Digit count
- 4
- Digit sum
- 14
- Digit product
- 36
- Digital root
- 5
- Palindrome
- No
- Bit width
- 12 bits
- Reversed
- 9,212
- Recamán's sequence
- a(3,493) = 2,129
- Square (n²)
- 4,532,641
- Cube (n³)
- 9,649,992,689
- Divisor count
- 2
- σ(n) — sum of divisors
- 2,130
- φ(n) — Euler's totient
- 2,128
Primality
2,129 is prime. It has exactly two divisors: 1 and itself.
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√2,129 = [46; (7, 11, 2, 1, 1, 4, 1, 4, 1, 17, 1, 1, 1, 2, 4, 2, 12, 1, 2, 1, 3, 3, 1, 2, …)]
Period length 43 — the block in parentheses repeats forever.
Representations
- In words
- two thousand one hundred twenty-nine
- Ordinal
- 2129th
- Roman numeral
- MMCXXIX
- Binary
- 100001010001
- Octal
- 4121
- Hexadecimal
- 0x851
- Base64
- CFE=
- One's complement
- 63,406 (16-bit)
- Scientific notation
- 2.129 × 10³
- As a duration
- 2,129 s = 35 minutes, 29 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓆼𓆼𓍢𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ͵βρκθʹ
- Mayan (base 20)
- 𝋥·𝋦·𝋩
- Chinese
- 二千一百二十九
- Chinese (financial)
- 貳仟壹佰貳拾玖
Digit at this position in famous constants
- π — Pi (π)
- Digit 2,129 = 1
- e — Euler's number (e)
- Digit 2,129 = 2
- φ — Golden ratio (φ)
- Digit 2,129 = 9
- √2 — Pythagoras's (√2)
- Digit 2,129 = 6
- ln 2 — Natural log of 2
- Digit 2,129 = 2
- γ — Euler-Mascheroni (γ)
- Digit 2,129 = 2
Also seen as
UTF-8 encoding: E0 A1 91 (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.8.81.
- Address
- 0.0.8.81
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.8.81
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 2,129 Hz is closest to:
- Concert pitch (A4 = 440 Hz): C7 (2093 Hz, +30¢)
- Scientific pitch (C4 = 256 Hz): C♯7 (2169.8 Hz, -33¢)
- Baroque pitch (A4 = 415 Hz): C♯7 (2091.5 Hz, +31¢)
The digit sequence 2129 first appears in π at position 711 of the decimal expansion (the 711ordinal-suffix:th 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.