18,221
18,221 is a composite number, odd.
18,221 (eighteen thousand two hundred twenty-one) is an odd 5-digit number. It is a composite number with 8 divisors, and factors as 7 × 19 × 137. Written other ways, in hexadecimal, 0x472D.
Interestingness
Properties
- Parity
- Odd
- Digit count
- 5
- Digit sum
- 14
- Digit product
- 32
- Digital root
- 5
- Palindrome
- No
- Bit width
- 15 bits
- Reversed
- 12,281
- Recamán's sequence
- a(15,438) = 18,221
- Square (n²)
- 332,004,841
- Cube (n³)
- 6,049,460,207,861
- Divisor count
- 8
- σ(n) — sum of divisors
- 22,080
- φ(n) — Euler's totient
- 14,688
- Sum of prime factors
- 163
Primality
Prime factorization: 7 × 19 × 137
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√18,221 = [134; (1, 66, 2, 66, 1, 268)]
Period length 6 — the block in parentheses repeats forever.
Representations
- In words
- eighteen thousand two hundred twenty-one
- Ordinal
- 18221st
- Binary
- 100011100101101
- Octal
- 43455
- Hexadecimal
- 0x472D
- Base64
- Ry0=
- One's complement
- 47,314 (16-bit)
- Scientific notation
- 1.8221 × 10⁴
- As a duration
- 18,221 s = 5 hours, 3 minutes, 41 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹 𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹
- Egyptian hieroglyphic
- 𓂍𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓍢𓍢𓎆𓎆𓏺
- Greek (Milesian)
- ͵ιησκαʹ
- Mayan (base 20)
- 𝋢·𝋥·𝋫·𝋡
- Chinese
- 一萬八千二百二十一
- Chinese (financial)
- 壹萬捌仟貳佰貳拾壹
Digit at this position in famous constants
- π — Pi (π)
- Digit 18,221 = 5
- e — Euler's number (e)
- Digit 18,221 = 2
- φ — Golden ratio (φ)
- Digit 18,221 = 8
- √2 — Pythagoras's (√2)
- Digit 18,221 = 3
- ln 2 — Natural log of 2
- Digit 18,221 = 1
- γ — Euler-Mascheroni (γ)
- Digit 18,221 = 2
Also seen as
UTF-8 encoding: E4 9C AD (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.71.45.
- Address
- 0.0.71.45
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.71.45
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 18,221 Hz is closest to:
- Concert pitch (A4 = 440 Hz): C♯10 (17739.7 Hz, +46¢ — about midway to D10)
- Scientific pitch (C4 = 256 Hz): D10 (18390.4 Hz, -16¢)
- Baroque pitch (A4 = 415 Hz): D10 (17726.7 Hz, +48¢ — about midway to D♯10)
The digit sequence 18221 first appears in π at position 273,367 of the decimal expansion (the 273,367ordinal-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.