12,840
12,840 is a composite number, even.
12,840 (twelve thousand eight hundred forty) is an even 5-digit number. It is a composite number with 32 divisors, and factors as 2³ × 3 × 5 × 107. Its proper divisors sum to 26,040, more than the number itself, making it an abundant number. Written other ways, in hexadecimal, 0x3228.
Interestingness
Properties
- Parity
- Even
- Digit count
- 5
- Digit sum
- 15
- Digit product
- 0
- Digital root
- 6
- Palindrome
- No
- Bit width
- 14 bits
- Reversed
- 4,821
- Recamán's sequence
- a(48,595) = 12,840
- Square (n²)
- 164,865,600
- Cube (n³)
- 2,116,874,304,000
- Divisor count
- 32
- σ(n) — sum of divisors
- 38,880
- φ(n) — Euler's totient
- 3,392
- Sum of prime factors
- 121
Primality
Prime factorization: 2 3 × 3 × 5 × 107
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√12,840 = [113; (3, 5, 3, 226)]
Period length 4 — the block in parentheses repeats forever.
Representations
- In words
- twelve thousand eight hundred forty
- Ordinal
- 12840th
- Binary
- 11001000101000
- Octal
- 31050
- Hexadecimal
- 0x3228
- Base64
- Mig=
- One's complement
- 52,695 (16-bit)
- Scientific notation
- 1.284 × 10⁴
- As a duration
- 12,840 s = 3 hours, 34 minutes
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹 𒌋𒌋𒌋𒁹𒁹𒁹𒁹 ·
- Egyptian hieroglyphic
- 𓂍𓆼𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆
- Greek (Milesian)
- ͵ιβωμʹ
- Mayan (base 20)
- 𝋡·𝋬·𝋢·𝋠
- Chinese
- 一萬二千八百四十
- Chinese (financial)
- 壹萬貳仟捌佰肆拾
Digit at this position in famous constants
- π — Pi (π)
- Digit 12,840 = 2
- e — Euler's number (e)
- Digit 12,840 = 4
- φ — Golden ratio (φ)
- Digit 12,840 = 3
- √2 — Pythagoras's (√2)
- Digit 12,840 = 6
- ln 2 — Natural log of 2
- Digit 12,840 = 5
- γ — Euler-Mascheroni (γ)
- Digit 12,840 = 8
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 12840, here are decompositions:
- 11 + 12829 = 12840
- 17 + 12823 = 12840
- 19 + 12821 = 12840
- 31 + 12809 = 12840
- 41 + 12799 = 12840
- 59 + 12781 = 12840
- 83 + 12757 = 12840
- 97 + 12743 = 12840
Showing the first eight; more decompositions exist.
UTF-8 encoding: E3 88 A8 (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.50.40.
- Address
- 0.0.50.40
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.50.40
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 12,840 Hz is closest to:
- Concert pitch (A4 = 440 Hz): G9 (12543.9 Hz, +40¢)
- Scientific pitch (C4 = 256 Hz): G♯9 (13004 Hz, -22¢)
- Baroque pitch (A4 = 415 Hz): G♯9 (12534.7 Hz, +42¢)
The digit sequence 12840 first appears in π at position 5,711 of the decimal expansion (the 5,711ordinal-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
- Babylonian numerals — The base-60 cuneiform system that gave us 60 minutes, 60 seconds, and 360°.