2,121
2,121 is a composite number, odd.
Properties
Primality
Prime factorization: 3 × 7 × 101
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- two thousand one hundred twenty-one
- Ordinal
- 2121st
- Roman numeral
- MMCXXI
- Binary
- 100001001001
- Octal
- 4111
- Hexadecimal
- 0x849
- Base64
- CEk=
- One's complement
- 63,414 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒁹
- Egyptian hieroglyphic
- 𓆼𓆼𓍢𓎆𓎆𓏺
- Greek (Milesian)
- ͵βρκαʹ
- Mayan (base 20)
- 𝋥·𝋦·𝋡
- Chinese
- 二千一百二十一
- Chinese (financial)
- 貳仟壹佰貳拾壹
Digit at this position in famous constants
- π — Pi (π)
- Digit 2,121 = 3
- e — Euler's number (e)
- Digit 2,121 = 3
- φ — Golden ratio (φ)
- Digit 2,121 = 4
- √2 — Pythagoras's (√2)
- Digit 2,121 = 9
- ln 2 — Natural log of 2
- Digit 2,121 = 3
- γ — Euler-Mascheroni (γ)
- Digit 2,121 = 8
Also seen as
UTF-8 encoding: E0 A1 89 (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.8.73.
- Address
- 0.0.8.73
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.8.73
Unspecified address (0.0.0.0/8) — "this network" placeholder.
This passes the ABA routing number checksum and matches the Federal Reserve numbering scheme.
Banks operate many routing numbers per state and division; an unmatched checksum-valid number can still be a real RTN at a smaller institution.
The digit sequence 2121 first appears in π at position 33,803 of the decimal expansion (the 33,803ordinal-suffix:rd 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.