21,138
21,138 is a composite number, even.
Properties
- Parity
- Even
- Digit count
- 5
- Digit sum
- 15
- Digit product
- 48
- Digital root
- 6
- Palindrome
- No
- Bit width
- 15 bits
- Reversed
- 83,112
- Recamán's sequence
- a(41,563) = 21,138
- Square (n²)
- 446,815,044
- Cube (n³)
- 9,444,776,400,072
- Divisor count
- 16
- σ(n) — sum of divisors
- 45,696
- φ(n) — Euler's totient
- 6,480
- Sum of prime factors
- 289
Primality
Prime factorization: 2 × 3 × 13 × 271
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- twenty-one thousand one hundred thirty-eight
- Ordinal
- 21138th
- Binary
- 101001010010010
- Octal
- 51222
- Hexadecimal
- 0x5292
- Base64
- UpI=
- One's complement
- 44,397 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹 𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓂍𓂍𓆼𓍢𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ͵καρληʹ
- Mayan (base 20)
- 𝋢·𝋬·𝋰·𝋲
- Chinese
- 二萬一千一百三十八
- Chinese (financial)
- 貳萬壹仟壹佰參拾捌
Digit at this position in famous constants
- π — Pi (π)
- Digit 21,138 = 7
- e — Euler's number (e)
- Digit 21,138 = 9
- φ — Golden ratio (φ)
- Digit 21,138 = 2
- √2 — Pythagoras's (√2)
- Digit 21,138 = 3
- ln 2 — Natural log of 2
- Digit 21,138 = 3
- γ — Euler-Mascheroni (γ)
- Digit 21,138 = 1
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 21138, here are decompositions:
- 17 + 21121 = 21138
- 31 + 21107 = 21138
- 37 + 21101 = 21138
- 71 + 21067 = 21138
- 79 + 21059 = 21138
- 107 + 21031 = 21138
- 127 + 21011 = 21138
- 137 + 21001 = 21138
Showing the first eight; more decompositions exist.
UTF-8 encoding: E5 8A 92 (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.146.
- Address
- 0.0.82.146
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.82.146
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 21138 first appears in π at position 60,589 of the decimal expansion (the 60,589ordinal-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.