21,428
21,428 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
- 82,412
- Recamán's sequence
- a(40,983) = 21,428
- Square (n²)
- 459,159,184
- Cube (n³)
- 9,838,862,994,752
- Divisor count
- 12
- σ(n) — sum of divisors
- 40,992
- φ(n) — Euler's totient
- 9,720
- Sum of prime factors
- 502
Primality
Prime factorization: 2 2 × 11 × 487
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- twenty-one thousand four hundred twenty-eight
- Ordinal
- 21428th
- Binary
- 101001110110100
- Octal
- 51664
- Hexadecimal
- 0x53B4
- Base64
- U7Q=
- One's complement
- 44,107 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓂍𓂍𓆼𓍢𓍢𓍢𓍢𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ͵καυκηʹ
- Mayan (base 20)
- 𝋢·𝋭·𝋫·𝋨
- Chinese
- 二萬一千四百二十八
- Chinese (financial)
- 貳萬壹仟肆佰貳拾捌
Digit at this position in famous constants
- π — Pi (π)
- Digit 21,428 = 5
- e — Euler's number (e)
- Digit 21,428 = 4
- φ — Golden ratio (φ)
- Digit 21,428 = 9
- √2 — Pythagoras's (√2)
- Digit 21,428 = 7
- ln 2 — Natural log of 2
- Digit 21,428 = 1
- γ — Euler-Mascheroni (γ)
- Digit 21,428 = 6
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 21428, here are decompositions:
- 31 + 21397 = 21428
- 37 + 21391 = 21428
- 109 + 21319 = 21428
- 151 + 21277 = 21428
- 181 + 21247 = 21428
- 241 + 21187 = 21428
- 271 + 21157 = 21428
- 307 + 21121 = 21428
Showing the first eight; more decompositions exist.
UTF-8 encoding: E5 8E B4 (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.83.180.
- Address
- 0.0.83.180
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.83.180
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 21428 first appears in π at position 28,051 of the decimal expansion (the 28,051ordinal-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.