21,988
21,988 is a composite number, even.
Properties
- Parity
- Even
- Digit count
- 5
- Digit sum
- 28
- Digit product
- 1,152
- Digital root
- 1
- Palindrome
- No
- Bit width
- 15 bits
- Reversed
- 88,912
- Recamán's sequence
- a(167,787) = 21,988
- Square (n²)
- 483,472,144
- Cube (n³)
- 10,630,585,502,272
- Divisor count
- 12
- σ(n) — sum of divisors
- 40,320
- φ(n) — Euler's totient
- 10,472
- Sum of prime factors
- 266
Primality
Prime factorization: 2 2 × 23 × 239
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- twenty-one thousand nine hundred eighty-eight
- Ordinal
- 21988th
- Binary
- 101010111100100
- Octal
- 52744
- Hexadecimal
- 0x55E4
- Base64
- VeQ=
- One's complement
- 43,547 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹𒁹 𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓂍𓂍𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ͵καϡπηʹ
- Mayan (base 20)
- 𝋢·𝋮·𝋳·𝋨
- Chinese
- 二萬一千九百八十八
- Chinese (financial)
- 貳萬壹仟玖佰捌拾捌
Digit at this position in famous constants
- π — Pi (π)
- Digit 21,988 = 0
- e — Euler's number (e)
- Digit 21,988 = 1
- φ — Golden ratio (φ)
- Digit 21,988 = 9
- √2 — Pythagoras's (√2)
- Digit 21,988 = 1
- ln 2 — Natural log of 2
- Digit 21,988 = 6
- γ — Euler-Mascheroni (γ)
- Digit 21,988 = 3
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 21988, here are decompositions:
- 11 + 21977 = 21988
- 59 + 21929 = 21988
- 107 + 21881 = 21988
- 137 + 21851 = 21988
- 149 + 21839 = 21988
- 167 + 21821 = 21988
- 251 + 21737 = 21988
- 389 + 21599 = 21988
Showing the first eight; more decompositions exist.
UTF-8 encoding: E5 97 A4 (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.85.228.
- Address
- 0.0.85.228
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.85.228
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 21988 first appears in π at position 88,544 of the decimal expansion (the 88,544ordinal-suffix:th 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.