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Number

21,487

21,487 is a prime, odd.

Cousin Prime Deficient Number Prime Sexy Prime Squarefree

Properties

Parity
Odd
Digit count
5
Digit sum
22
Digital root
4
Palindrome
No
Divisor count
2
σ(n) — sum of divisors
21,488

Primality

21,487 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 21487
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 21,487)
1 × 21487
First multiples
21,487 · 42,974 · 64,461 · 85,948 · 107,435 · 128,922 · 150,409 · 171,896 · 193,383 · 214,870

Representations

In words
twenty-one thousand four hundred eighty-seven
Ordinal
21487th
Binary
101001111101111
Octal
51757
Hexadecimal
53EF

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 21,481 (gap of 6)
  • Next prime: 21,491 (gap of 4)

Pair status: cousin with 21491, sexy with 21481.

Unicode codepoint
U+53EF
Other letter (Lo)

UTF-8 encoding: E5 8F AF (3 bytes).

Hex color
#0053EF
RGB(0, 83, 239)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.83.239.

Possible US bank routing number

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

Routing number
000021487
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.