Number
21,221
21,221 is a prime, odd.
Properties
- Parity
- Odd
- Digit count
- 5
- Digit sum
- 8
- Digit product
- 8
- Digital root
- 8
- Palindrome
- No
- Bit width
- 15 bits
- Reversed
- 12,212
- Recamán's sequence
- a(41,397) = 21,221
- Square (n²)
- 450,330,841
- Cube (n³)
- 9,556,470,776,861
- Divisor count
- 2
- σ(n) — sum of divisors
- 21,222
- φ(n) — Euler's totient
- 21,220
Primality
21,221 is prime. It has exactly two divisors: 1 and itself.
Divisors & multiples
Aliquot sum (sum of proper divisors):
1
First multiples
21,221
·
42,442
(double)
·
63,663
·
84,884
·
106,105
·
127,326
·
148,547
·
169,768
·
190,989
·
212,210
Sums & aliquot sequence
As a sum of two squares:
14² + 145²
As consecutive integers:
10,610 + 10,611
Representations
- In words
- twenty-one thousand two hundred twenty-one
- Ordinal
- 21221st
- Binary
- 101001011100101
- Octal
- 51345
- Hexadecimal
- 0x52E5
- Base64
- UuU=
- One's complement
- 44,314 (16-bit)
In other bases
ternary (3)
1002002222
quaternary (4)
11023211
quinary (5)
1134341
senary (6)
242125
septenary (7)
115604
nonary (9)
32088
undecimal (11)
14a42
duodecimal (12)
10345
tridecimal (13)
9875
tetradecimal (14)
7a3b
pentadecimal (15)
644b
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹
- Egyptian hieroglyphic
- 𓂍𓂍𓆼𓍢𓍢𓎆𓎆𓏺
- Greek (Milesian)
- ͵κασκαʹ
- Mayan (base 20)
- 𝋢·𝋭·𝋡·𝋡
- Chinese
- 二萬一千二百二十一
- Chinese (financial)
- 貳萬壹仟貳佰貳拾壹
In other modern scripts
Eastern Arabic
٢١٢٢١
Devanagari
२१२२१
Bengali
২১২২১
Tamil
௨௧௨௨௧
Thai
๒๑๒๒๑
Tibetan
༢༡༢༢༡
Khmer
២១២២១
Lao
໒໑໒໒໑
Burmese
၂၁၂၂၁
Digit at this position in famous constants
- π — Pi (π)
- Digit 21,221 = 5
- e — Euler's number (e)
- Digit 21,221 = 3
- φ — Golden ratio (φ)
- Digit 21,221 = 5
- √2 — Pythagoras's (√2)
- Digit 21,221 = 5
- ln 2 — Natural log of 2
- Digit 21,221 = 1
- γ — Euler-Mascheroni (γ)
- Digit 21,221 = 1
Also seen as
Prime neighborhood
Unicode codepoint
勥
CJK Unified Ideograph-52E5
U+52E5
Other letter (Lo)
UTF-8 encoding: E5 8B A5 (3 bytes).
Hex color
#0052E5
RGB(0, 82, 229)
IPv4 address
As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.229.
- Address
- 0.0.82.229
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.82.229
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Position in π
The digit sequence 21221 first appears in π at position 8,730 of the decimal expansion (the 8,730ordinal-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.