21,842
21,842 is a composite number, even.
Properties
- Parity
- Even
- Digit count
- 5
- Digit sum
- 17
- Digit product
- 128
- Digital root
- 8
- Palindrome
- No
- Bit width
- 15 bits
- Reversed
- 24,812
- Recamán's sequence
- a(168,079) = 21,842
- Square (n²)
- 477,072,964
- Cube (n³)
- 10,420,227,679,688
- Divisor count
- 8
- σ(n) — sum of divisors
- 33,456
- φ(n) — Euler's totient
- 10,692
- Sum of prime factors
- 232
Primality
Prime factorization: 2 × 67 × 163
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- twenty-one thousand eight hundred forty-two
- Ordinal
- 21842nd
- Binary
- 101010101010010
- Octal
- 52522
- Hexadecimal
- 0x5552
- Base64
- VVI=
- One's complement
- 43,693 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹𒁹 𒁹𒁹𒁹𒁹 𒁹𒁹
- Egyptian hieroglyphic
- 𓂍𓂍𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓏺𓏺
- Greek (Milesian)
- ͵καωμβʹ
- Mayan (base 20)
- 𝋢·𝋮·𝋬·𝋢
- Chinese
- 二萬一千八百四十二
- Chinese (financial)
- 貳萬壹仟捌佰肆拾貳
Digit at this position in famous constants
- π — Pi (π)
- Digit 21,842 = 8
- e — Euler's number (e)
- Digit 21,842 = 9
- φ — Golden ratio (φ)
- Digit 21,842 = 2
- √2 — Pythagoras's (√2)
- Digit 21,842 = 6
- ln 2 — Natural log of 2
- Digit 21,842 = 3
- γ — Euler-Mascheroni (γ)
- Digit 21,842 = 1
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 21842, here are decompositions:
- 3 + 21839 = 21842
- 43 + 21799 = 21842
- 103 + 21739 = 21842
- 181 + 21661 = 21842
- 193 + 21649 = 21842
- 229 + 21613 = 21842
- 241 + 21601 = 21842
- 283 + 21559 = 21842
Showing the first eight; more decompositions exist.
UTF-8 encoding: E5 95 92 (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.85.82.
- Address
- 0.0.85.82
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.85.82
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 21842 first appears in π at position 1,737 of the decimal expansion (the 1,737ordinal-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.