number.wiki
Number

521

521 is a prime, odd, a calendar year.

Deficient Number Lucas Prime Squarefree Twin Prime Year

Properties

Parity
Odd
Digit count
3
Digit sum
8
Digital root
8
Palindrome
No
Divisor count
2
σ(n) — sum of divisors
522

Primality

521 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 521
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 521)
1 × 521
First multiples
521 · 1,042 · 1,563 · 2,084 · 2,605 · 3,126 · 3,647 · 4,168 · 4,689 · 5,210

Representations

In words
five hundred twenty-one
Ordinal
521st
Roman numeral
DXXI
Binary
1000001001
Octal
1011
Hexadecimal
209

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 509 (gap of 12)
  • Next prime: 523 (gap of 2)

Pair status: twin with 523.

Unicode codepoint
ȉ
U+0209
Lowercase letter (Ll)

UTF-8 encoding: C8 89 (2 bytes).

Hex color
#000209
RGB(0, 2, 9)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.2.9.

Possible US bank routing number

This passes the ABA routing number checksum and matches the Federal Reserve numbering scheme.

Routing number
000000521
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.