21,408
21,408 is a composite number, even.
Properties
- Parity
- Even
- Digit count
- 5
- Digit sum
- 15
- Digit product
- 0
- Digital root
- 6
- Palindrome
- No
- Bit width
- 15 bits
- Reversed
- 80,412
- Recamán's sequence
- a(41,023) = 21,408
- Square (n²)
- 458,302,464
- Cube (n³)
- 9,811,339,149,312
- Divisor count
- 24
- σ(n) — sum of divisors
- 56,448
- φ(n) — Euler's totient
- 7,104
- Sum of prime factors
- 236
Primality
Prime factorization: 2 5 × 3 × 223
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- twenty-one thousand four hundred eight
- Ordinal
- 21408th
- Binary
- 101001110100000
- Octal
- 51640
- Hexadecimal
- 0x53A0
- Base64
- U6A=
- One's complement
- 44,127 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓂍𓂍𓆼𓍢𓍢𓍢𓍢𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ͵καυηʹ
- Mayan (base 20)
- 𝋢·𝋭·𝋪·𝋨
- Chinese
- 二萬一千四百零八
- Chinese (financial)
- 貳萬壹仟肆佰零捌
Digit at this position in famous constants
- π — Pi (π)
- Digit 21,408 = 5
- e — Euler's number (e)
- Digit 21,408 = 4
- φ — Golden ratio (φ)
- Digit 21,408 = 9
- √2 — Pythagoras's (√2)
- Digit 21,408 = 4
- ln 2 — Natural log of 2
- Digit 21,408 = 4
- γ — Euler-Mascheroni (γ)
- Digit 21,408 = 6
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 21408, here are decompositions:
- 7 + 21401 = 21408
- 11 + 21397 = 21408
- 17 + 21391 = 21408
- 29 + 21379 = 21408
- 31 + 21377 = 21408
- 61 + 21347 = 21408
- 67 + 21341 = 21408
- 89 + 21319 = 21408
Showing the first eight; more decompositions exist.
UTF-8 encoding: E5 8E A0 (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.83.160.
- Address
- 0.0.83.160
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.83.160
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 21408 first appears in π at position 8,433 of the decimal expansion (the 8,433ordinal-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.