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Number

21,247

21,247 is a prime, odd.

Arithmetic Number Deficient Number Odious Number Pernicious Number Prime Recamán's Sequence Self Number Squarefree

Properties

Parity
Odd
Digit count
5
Digit sum
16
Digit product
112
Digital root
7
Palindrome
No
Bit width
15 bits
Reversed
74,212
Recamán's sequence
a(41,345) = 21,247
Square (n²)
451,435,009
Cube (n³)
9,591,639,636,223
Divisor count
2
σ(n) — sum of divisors
21,248
φ(n) — Euler's totient
21,246

Primality

21,247 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 21247
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 21,247)
1 × 21247
First multiples
21,247 · 42,494 (double) · 63,741 · 84,988 · 106,235 · 127,482 · 148,729 · 169,976 · 191,223 · 212,470

Sums & aliquot sequence

As consecutive integers: 10,623 + 10,624

Representations

In words
twenty-one thousand two hundred forty-seven
Ordinal
21247th
Binary
101001011111111
Octal
51377
Hexadecimal
0x52FF
Base64
Uv8=
One's complement
44,288 (16-bit)
In other bases
ternary (3) 1002010221
quaternary (4) 11023333
quinary (5) 1134442
senary (6) 242211
septenary (7) 115642
nonary (9) 32127
undecimal (11) 14a66
duodecimal (12) 10367
tridecimal (13) 9895
tetradecimal (14) 7a59
pentadecimal (15) 6467

Historical numeral systems

Babylonian (base 60)
𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹 𒁹𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic
𓂍𓂍𓆼𓍢𓍢𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian)
͵κασμζʹ
Mayan (base 20)
𝋢·𝋭·𝋢·𝋧
Chinese
二萬一千二百四十七
Chinese (financial)
貳萬壹仟貳佰肆拾柒
In other modern scripts
Eastern Arabic ٢١٢٤٧ Devanagari २१२४७ Bengali ২১২৪৭ Tamil ௨௧௨௪௭ Thai ๒๑๒๔๗ Tibetan ༢༡༢༤༧ Khmer ២១២៤៧ Lao ໒໑໒໔໗ Burmese ၂၁၂၄၇

Digit at this position in famous constants

π — Pi (π)
Digit 21,247 = 6
e — Euler's number (e)
Digit 21,247 = 5
φ — Golden ratio (φ)
Digit 21,247 = 8
√2 — Pythagoras's (√2)
Digit 21,247 = 7
ln 2 — Natural log of 2
Digit 21,247 = 3
γ — Euler-Mascheroni (γ)
Digit 21,247 = 8

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 21,227 (gap of 20)
  • Next prime: 21,269 (gap of 22)
Unicode codepoint
CJK Unified Ideograph-52Ff
U+52FF
Other letter (Lo)

UTF-8 encoding: E5 8B BF (3 bytes).

Hex color
#0052FF
RGB(0, 82, 255)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.255.

Address
0.0.82.255
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.82.255

Unspecified address (0.0.0.0/8) — "this network" placeholder.

Position in π

The digit sequence 21247 first appears in π at position 27,068 of the decimal expansion (the 27,068ordinal-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.