Number
1,821
1,821 is a composite number, odd, a calendar year.
Properties
- Parity
- Odd
- Digit count
- 4
- Digit sum
- 12
- Digital root
- 3
- Palindrome
- No
- Divisor count
- 4
- σ(n) — sum of divisors
- 2,432
Primality
Prime factorization: 3 × 607
Divisors & multiples
Aliquot sum (sum of proper divisors):
611
First multiples
Representations
- In words
- one thousand eight hundred twenty-one
- Ordinal
- 1821st
- Roman numeral
- MDCCCXXI
- Binary
- 11100011101
- Octal
- 3435
- Hexadecimal
- 71D
Also seen as
Unicode codepoint
ܝ
U+071D
Other letter (Lo)
UTF-8 encoding: DC 9D (2 bytes).
Hex color
#00071D
RGB(0, 7, 29)
IPv4 address
As an unsigned 32-bit integer, this is the IPv4 address 0.0.7.29.
Possible US bank routing number
This passes the ABA routing number checksum and matches the Federal Reserve numbering scheme.
Routing number
000001821
Federal Reserve
United States Government
Banks operate many routing numbers per state and division; an unmatched checksum-valid number can still be a real RTN at a smaller institution.