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21,970

21,970 is a composite number, even.

This number doesn't have a permanent NumberWiki page yet — what you see below is computed live. Pages get added to the permanent index when they're notable (years, primes, curated, etc.).
Deficient Number Evil Number Recamán's Sequence Smith Number

Properties

Parity
Even
Digit count
5
Digit sum
19
Digit product
0
Digital root
1
Palindrome
No
Bit width
15 bits
Reversed
7,912
Recamán's sequence
a(167,823) = 21,970
Square (n²)
482,680,900
Cube (n³)
10,604,499,373,000
Divisor count
16
σ(n) — sum of divisors
42,840
φ(n) — Euler's totient
8,112
Sum of prime factors
46

Primality

Prime factorization: 2 × 5 × 13 3

Nearest primes: 21,961 (−9) · 21,977 (+7)

Divisors & multiples

All divisors (16)
1 · 2 · 5 · 10 · 13 · 26 · 65 · 130 · 169 · 338 · 845 · 1690 · 2197 · 4394 · 10985 (half) · 21970
Aliquot sum (sum of proper divisors): 20,870
Factor pairs (a × b = 21,970)
1 × 21970
2 × 10985
5 × 4394
10 × 2197
13 × 1690
26 × 845
65 × 338
130 × 169
First multiples
21,970 · 43,940 (double) · 65,910 · 87,880 · 109,850 · 131,820 · 153,790 · 175,760 · 197,730 · 219,700

Sums & aliquot sequence

As a sum of two squares: 19² + 147² = 39² + 143² = 73² + 129² = 91² + 117²
As consecutive integers: 5,491 + 5,492 + 5,493 + 5,494 4,392 + 4,393 + 4,394 + 4,395 + 4,396 1,684 + 1,685 + … + 1,696 1,089 + 1,090 + … + 1,108
Aliquot sequence: 21,970 20,870 16,714 8,954 6,208 6,238 3,122 2,254 1,850 1,684 1,270 1,034 694 350 394 200 265 — unresolved within range

Representations

In words
twenty-one thousand nine hundred seventy
Ordinal
21970th
Binary
101010111010010
Octal
52722
Hexadecimal
0x55D2
Base64
VdI=
One's complement
43,565 (16-bit)
In other bases
ternary (3) 1010010201
quaternary (4) 11113102
quinary (5) 1200340
senary (6) 245414
septenary (7) 121024
nonary (9) 33121
undecimal (11) 15563
duodecimal (12) 1086a
tridecimal (13) a000
tetradecimal (14) 8014
pentadecimal (15) 679a

Historical numeral systems

Babylonian (base 60)
𒁹𒁹𒁹𒁹𒁹𒁹 𒁹𒁹𒁹𒁹𒁹𒁹 𒌋
Egyptian hieroglyphic
𓂍𓂍𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆
Greek (Milesian)
͵καϡοʹ
Mayan (base 20)
𝋢·𝋮·𝋲·𝋪
Chinese
二萬一千九百七十
Chinese (financial)
貳萬壹仟玖佰柒拾
In other modern scripts
Eastern Arabic ٢١٩٧٠ Devanagari २१९७० Bengali ২১৯৭০ Tamil ௨௧௯௭௦ Thai ๒๑๙๗๐ Tibetan ༢༡༩༧༠ Khmer ២១៩៧០ Lao ໒໑໙໗໐ Burmese ၂၁၉၇၀

Digit at this position in famous constants

π — Pi (π)
Digit 21,970 = 4
e — Euler's number (e)
Digit 21,970 = 9
φ — Golden ratio (φ)
Digit 21,970 = 4
√2 — Pythagoras's (√2)
Digit 21,970 = 3
ln 2 — Natural log of 2
Digit 21,970 = 1
γ — Euler-Mascheroni (γ)
Digit 21,970 = 7

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 21970, here are decompositions:

  • 41 + 21929 = 21970
  • 59 + 21911 = 21970
  • 89 + 21881 = 21970
  • 107 + 21863 = 21970
  • 131 + 21839 = 21970
  • 149 + 21821 = 21970
  • 167 + 21803 = 21970
  • 197 + 21773 = 21970

Showing the first eight; more decompositions exist.

Unicode codepoint
CJK Unified Ideograph-55D2
U+55D2
Other letter (Lo)

UTF-8 encoding: E5 97 92 (3 bytes).

Hex color
#0055D2
RGB(0, 85, 210)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.85.210.

Address
0.0.85.210
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.85.210

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

Position in π

The digit sequence 21970 first appears in π at position 30,992 of the decimal expansion (the 30,992ordinal-suffix:nd 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.