21,920
21,920 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
- 2,912
- Recamán's sequence
- a(167,923) = 21,920
- Square (n²)
- 480,486,400
- Cube (n³)
- 10,532,261,888,000
- Divisor count
- 24
- σ(n) — sum of divisors
- 52,164
- φ(n) — Euler's totient
- 8,704
- Sum of prime factors
- 152
Primality
Prime factorization: 2 5 × 5 × 137
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- twenty-one thousand nine hundred twenty
- Ordinal
- 21920th
- Binary
- 101010110100000
- Octal
- 52640
- Hexadecimal
- 0x55A0
- Base64
- VaA=
- One's complement
- 43,615 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹𒁹 𒁹𒁹𒁹𒁹𒁹 𒌋𒌋
- Egyptian hieroglyphic
- 𓂍𓂍𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆
- Greek (Milesian)
- ͵καϡκʹ
- Mayan (base 20)
- 𝋢·𝋮·𝋰·𝋠
- Chinese
- 二萬一千九百二十
- Chinese (financial)
- 貳萬壹仟玖佰貳拾
Digit at this position in famous constants
- π — Pi (π)
- Digit 21,920 = 9
- e — Euler's number (e)
- Digit 21,920 = 7
- φ — Golden ratio (φ)
- Digit 21,920 = 7
- √2 — Pythagoras's (√2)
- Digit 21,920 = 9
- ln 2 — Natural log of 2
- Digit 21,920 = 7
- γ — Euler-Mascheroni (γ)
- Digit 21,920 = 0
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 21920, here are decompositions:
- 61 + 21859 = 21920
- 79 + 21841 = 21920
- 103 + 21817 = 21920
- 163 + 21757 = 21920
- 181 + 21739 = 21920
- 193 + 21727 = 21920
- 271 + 21649 = 21920
- 307 + 21613 = 21920
Showing the first eight; more decompositions exist.
UTF-8 encoding: E5 96 A0 (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.85.160.
- Address
- 0.0.85.160
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.85.160
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 21920 first appears in π at position 361,103 of the decimal expansion (the 361,103ordinal-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.