21,380
21,380 is a composite number, even.
Properties
- Parity
- Even
- Digit count
- 5
- Digit sum
- 14
- Digit product
- 0
- Digital root
- 5
- Palindrome
- No
- Bit width
- 15 bits
- Reversed
- 8,312
- Recamán's sequence
- a(41,079) = 21,380
- Square (n²)
- 457,104,400
- Cube (n³)
- 9,772,892,072,000
- Divisor count
- 12
- σ(n) — sum of divisors
- 44,940
- φ(n) — Euler's totient
- 8,544
- Sum of prime factors
- 1,078
Primality
Prime factorization: 2 2 × 5 × 1069
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- twenty-one thousand three hundred eighty
- Ordinal
- 21380th
- Binary
- 101001110000100
- Octal
- 51604
- Hexadecimal
- 0x5384
- Base64
- U4Q=
- One's complement
- 44,155 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋
- Egyptian hieroglyphic
- 𓂍𓂍𓆼𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆
- Greek (Milesian)
- ͵κατπʹ
- Mayan (base 20)
- 𝋢·𝋭·𝋩·𝋠
- Chinese
- 二萬一千三百八十
- Chinese (financial)
- 貳萬壹仟參佰捌拾
Digit at this position in famous constants
- π — Pi (π)
- Digit 21,380 = 0
- e — Euler's number (e)
- Digit 21,380 = 6
- φ — Golden ratio (φ)
- Digit 21,380 = 9
- √2 — Pythagoras's (√2)
- Digit 21,380 = 7
- ln 2 — Natural log of 2
- Digit 21,380 = 4
- γ — Euler-Mascheroni (γ)
- Digit 21,380 = 3
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 21380, here are decompositions:
- 3 + 21377 = 21380
- 61 + 21319 = 21380
- 67 + 21313 = 21380
- 97 + 21283 = 21380
- 103 + 21277 = 21380
- 193 + 21187 = 21380
- 211 + 21169 = 21380
- 223 + 21157 = 21380
Showing the first eight; more decompositions exist.
UTF-8 encoding: E5 8E 84 (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.83.132.
- Address
- 0.0.83.132
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.83.132
Unspecified address (0.0.0.0/8) — "this network" placeholder.
This passes the ABA routing number checksum and matches the Federal Reserve numbering scheme.
Banks operate many routing numbers per state and division; an unmatched checksum-valid number can still be a real RTN at a smaller institution.
The digit sequence 21380 first appears in π at position 55,471 of the decimal expansion (the 55,471ordinal-suffix:st 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.