Number
20,921
20,921 is a prime, odd.
Properties
- Parity
- Odd
- Digit count
- 5
- Digit sum
- 14
- Digit product
- 0
- Digital root
- 5
- Palindrome
- No
- Bit width
- 15 bits
- Reversed
- 12,902
- Recamán's sequence
- a(41,997) = 20,921
- Square (n²)
- 437,688,241
- Cube (n³)
- 9,156,875,689,961
- Divisor count
- 2
- σ(n) — sum of divisors
- 20,922
- φ(n) — Euler's totient
- 20,920
Primality
20,921 is prime. It has exactly two divisors: 1 and itself.
Divisors & multiples
Aliquot sum (sum of proper divisors):
1
First multiples
20,921
·
41,842
(double)
·
62,763
·
83,684
·
104,605
·
125,526
·
146,447
·
167,368
·
188,289
·
209,210
Sums & aliquot sequence
As a sum of two squares:
40² + 139²
As consecutive integers:
10,460 + 10,461
Representations
- In words
- twenty thousand nine hundred twenty-one
- Ordinal
- 20921st
- Binary
- 101000110111001
- Octal
- 50671
- Hexadecimal
- 0x51B9
- Base64
- Ubk=
- One's complement
- 44,614 (16-bit)
In other bases
ternary (3)
1001200212
quaternary (4)
11012321
quinary (5)
1132141
senary (6)
240505
septenary (7)
114665
nonary (9)
31625
undecimal (11)
1479a
duodecimal (12)
10135
tridecimal (13)
96a4
tetradecimal (14)
78a5
pentadecimal (15)
62eb
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹
- Egyptian hieroglyphic
- 𓂍𓂍𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓏺
- Greek (Milesian)
- ͵κϡκαʹ
- Mayan (base 20)
- 𝋢·𝋬·𝋦·𝋡
- Chinese
- 二萬零九百二十一
- Chinese (financial)
- 貳萬零玖佰貳拾壹
In other modern scripts
Eastern Arabic
٢٠٩٢١
Devanagari
२०९२१
Bengali
২০৯২১
Tamil
௨௦௯௨௧
Thai
๒๐๙๒๑
Tibetan
༢༠༩༢༡
Khmer
២០៩២១
Lao
໒໐໙໒໑
Burmese
၂၀၉၂၁
Digit at this position in famous constants
- π — Pi (π)
- Digit 20,921 = 5
- e — Euler's number (e)
- Digit 20,921 = 7
- φ — Golden ratio (φ)
- Digit 20,921 = 2
- √2 — Pythagoras's (√2)
- Digit 20,921 = 7
- ln 2 — Natural log of 2
- Digit 20,921 = 6
- γ — Euler-Mascheroni (γ)
- Digit 20,921 = 5
Also seen as
Unicode codepoint
冹
CJK Unified Ideograph-51B9
U+51B9
Other letter (Lo)
UTF-8 encoding: E5 86 B9 (3 bytes).
Hex color
#0051B9
RGB(0, 81, 185)
IPv4 address
As an unsigned 32-bit integer, this is the IPv4 address 0.0.81.185.
- Address
- 0.0.81.185
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.81.185
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Position in π
The digit sequence 20921 first appears in π at position 49,087 of the decimal expansion (the 49,087ordinal-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.