2,221
2,221 is a prime, odd.
2,221 (two thousand two hundred twenty-one) is an odd 4-digit number. It is a prime number — divisible only by 1 and itself. Written other ways, in Roman numerals it is MMCCXXI and in binary, 100010101101.
Interestingness
Properties
Primality
2,221 is prime. It has exactly two divisors: 1 and itself.
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√2,221 = [47; (7, 1, 5, 2, 2, 4, 3, 3, 1, 3, 1, 2, 1, 1, 2, 1, 3, 1, 3, 3, 4, 2, 2, 5, …)]
Period length 27 — the block in parentheses repeats forever.
Representations
- In words
- two thousand two hundred twenty-one
- Ordinal
- 2221st
- Roman numeral
- MMCCXXI
- Binary
- 100010101101
- Octal
- 4255
- Hexadecimal
- 0x8AD
- Base64
- CK0=
- One's complement
- 63,314 (16-bit)
- Scientific notation
- 2.221 × 10³
- As a duration
- 2,221 s = 37 minutes, 1 second
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒁹
- Egyptian hieroglyphic
- 𓆼𓆼𓍢𓍢𓎆𓎆𓏺
- Greek (Milesian)
- ͵βσκαʹ
- Mayan (base 20)
- 𝋥·𝋫·𝋡
- Chinese
- 二千二百二十一
- Chinese (financial)
- 貳仟貳佰貳拾壹
Digit at this position in famous constants
- π — Pi (π)
- Digit 2,221 = 1
- e — Euler's number (e)
- Digit 2,221 = 7
- φ — Golden ratio (φ)
- Digit 2,221 = 7
- √2 — Pythagoras's (√2)
- Digit 2,221 = 3
- ln 2 — Natural log of 2
- Digit 2,221 = 3
- γ — Euler-Mascheroni (γ)
- Digit 2,221 = 0
Also seen as
UTF-8 encoding: E0 A2 AD (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.8.173.
- Address
- 0.0.8.173
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.8.173
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 2,221 Hz is closest to:
- Concert pitch (A4 = 440 Hz): C♯7 (2217.5 Hz, +3¢)
- Scientific pitch (C4 = 256 Hz): C♯7 (2169.8 Hz, +40¢)
- Baroque pitch (A4 = 415 Hz): D7 (2215.8 Hz, +4¢)
The digit sequence 2221 first appears in π at position 1,735 of the decimal expansion (the 1,735ordinal-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
- Prime numbers — The building blocks of arithmetic: what primes are, why they matter, and how we find them.
- Egyptian hieroglyphic numerals — Seven hieroglyphs for every power of ten, from a single stroke to a million.