21,838
21,838 is a composite number, even.
21,838 (twenty-one thousand eight hundred thirty-eight) is an even 5-digit number. It is a composite number with 8 divisors, and factors as 2 × 61 × 179. Written other ways, in hexadecimal, 0x554E.
Interestingness
Properties
- Parity
- Even
- Digit count
- 5
- Digit sum
- 22
- Digit product
- 384
- Digital root
- 4
- Palindrome
- No
- Bit width
- 15 bits
- Reversed
- 83,812
- Recamán's sequence
- a(168,087) = 21,838
- Square (n²)
- 476,898,244
- Cube (n³)
- 10,414,503,852,472
- Divisor count
- 8
- σ(n) — sum of divisors
- 33,480
- φ(n) — Euler's totient
- 10,680
- Sum of prime factors
- 242
Primality
Prime factorization: 2 × 61 × 179
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√21,838 = [147; (1, 3, 2, 12, 1, 97, 1, 1, 2, 4, 1, 3, 1, 1, 1, 32, 5, 15, 2, 1, 4, 10, 1, 2, …)]
Period length 58 — the block in parentheses repeats forever.
Representations
- In words
- twenty-one thousand eight hundred thirty-eight
- Ordinal
- 21838th
- Binary
- 101010101001110
- Octal
- 52516
- Hexadecimal
- 0x554E
- Base64
- VU4=
- One's complement
- 43,697 (16-bit)
- Scientific notation
- 2.1838 × 10⁴
- As a duration
- 21,838 s = 6 hours, 3 minutes, 58 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹𒁹 𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓂍𓂍𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ͵καωληʹ
- Mayan (base 20)
- 𝋢·𝋮·𝋫·𝋲
- Chinese
- 二萬一千八百三十八
- Chinese (financial)
- 貳萬壹仟捌佰參拾捌
Digit at this position in famous constants
- π — Pi (π)
- Digit 21,838 = 5
- e — Euler's number (e)
- Digit 21,838 = 2
- φ — Golden ratio (φ)
- Digit 21,838 = 6
- √2 — Pythagoras's (√2)
- Digit 21,838 = 3
- ln 2 — Natural log of 2
- Digit 21,838 = 5
- γ — Euler-Mascheroni (γ)
- Digit 21,838 = 1
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 21838, here are decompositions:
- 17 + 21821 = 21838
- 71 + 21767 = 21838
- 101 + 21737 = 21838
- 137 + 21701 = 21838
- 191 + 21647 = 21838
- 227 + 21611 = 21838
- 239 + 21599 = 21838
- 251 + 21587 = 21838
Showing the first eight; more decompositions exist.
UTF-8 encoding: E5 95 8E (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.85.78.
- Address
- 0.0.85.78
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.85.78
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 21838 first appears in π at position 327,793 of the decimal expansion (the 327,793ordinal-suffix:rd 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
- Egyptian hieroglyphic numerals — Seven hieroglyphs for every power of ten, from a single stroke to a million.