2,138
2,138 is a composite number, even.
2,138 (two thousand one hundred thirty-eight) is an even 4-digit number. It is a composite number with 4 divisors, and factors as 2 × 1,069. Written other ways, in Roman numerals it is MMCXXXVIII and in binary, 100001011010.
Interestingness
Properties
- Parity
- Even
- Digit count
- 4
- Digit sum
- 14
- Digit product
- 48
- Digital root
- 5
- Palindrome
- No
- Bit width
- 12 bits
- Reversed
- 8,312
- Recamán's sequence
- a(3,475) = 2,138
- Square (n²)
- 4,571,044
- Cube (n³)
- 9,772,892,072
- Divisor count
- 4
- σ(n) — sum of divisors
- 3,210
- φ(n) — Euler's totient
- 1,068
- Sum of prime factors
- 1,071
Primality
Prime factorization: 2 × 1069
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√2,138 = [46; (4, 5, 5, 4, 92)]
Period length 5 — the block in parentheses repeats forever.
Representations
- In words
- two thousand one hundred thirty-eight
- Ordinal
- 2138th
- Roman numeral
- MMCXXXVIII
- Binary
- 100001011010
- Octal
- 4132
- Hexadecimal
- 0x85A
- Base64
- CFo=
- One's complement
- 63,397 (16-bit)
- Scientific notation
- 2.138 × 10³
- As a duration
- 2,138 s = 35 minutes, 38 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓆼𓆼𓍢𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ͵βρληʹ
- Mayan (base 20)
- 𝋥·𝋦·𝋲
- Chinese
- 二千一百三十八
- Chinese (financial)
- 貳仟壹佰參拾捌
Digit at this position in famous constants
- π — Pi (π)
- Digit 2,138 = 9
- e — Euler's number (e)
- Digit 2,138 = 5
- φ — Golden ratio (φ)
- Digit 2,138 = 9
- √2 — Pythagoras's (√2)
- Digit 2,138 = 4
- ln 2 — Natural log of 2
- Digit 2,138 = 1
- γ — Euler-Mascheroni (γ)
- Digit 2,138 = 0
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 2138, here are decompositions:
- 7 + 2131 = 2138
- 109 + 2029 = 2138
- 127 + 2011 = 2138
- 139 + 1999 = 2138
- 151 + 1987 = 2138
- 271 + 1867 = 2138
- 277 + 1861 = 2138
- 307 + 1831 = 2138
Showing the first eight; more decompositions exist.
UTF-8 encoding: E0 A1 9A (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.8.90.
- Address
- 0.0.8.90
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.8.90
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 2,138 Hz is closest to:
- Concert pitch (A4 = 440 Hz): C7 (2093 Hz, +37¢)
- Scientific pitch (C4 = 256 Hz): C♯7 (2169.8 Hz, -26¢)
- Baroque pitch (A4 = 415 Hz): C♯7 (2091.5 Hz, +38¢)
The digit sequence 2138 first appears in π at position 380 of the decimal expansion (the 380ordinal-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.
Related reading
- Mayan numerals — Vigesimal dots-and-bars with a shell zero — one of the earliest true zeros.