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Number

16,981

16,981 is a prime, odd.

Arithmetic Number Deficient Number Evil Number Flippable Prime Pythagorean Prime Recamán's Sequence Sexy Prime Squarefree Twin Prime

Properties

Parity
Odd
Digit count
5
Digit sum
25
Digit product
432
Digital root
7
Palindrome
No
Bit width
15 bits
Reversed
18,961
Flips to (rotate 180°)
18,691
Recamán's sequence
a(44,449) = 16,981
Square (n²)
288,354,361
Cube (n³)
4,896,545,404,141
Divisor count
2
σ(n) — sum of divisors
16,982
φ(n) — Euler's totient
16,980

Primality

16,981 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 16981
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 16,981)
1 × 16981
First multiples
16,981 · 33,962 (double) · 50,943 · 67,924 · 84,905 · 101,886 · 118,867 · 135,848 · 152,829 · 169,810

Sums & aliquot sequence

As a sum of two squares: 9² + 130²
As consecutive integers: 8,490 + 8,491

Representations

In words
sixteen thousand nine hundred eighty-one
Ordinal
16981st
Binary
100001001010101
Octal
41125
Hexadecimal
0x4255
Base64
QlU=
One's complement
48,554 (16-bit)
In other bases
ternary (3) 212021221
quaternary (4) 10021111
quinary (5) 1020411
senary (6) 210341
septenary (7) 100336
nonary (9) 25257
undecimal (11) 11838
duodecimal (12) 99b1
tridecimal (13) 7963
tetradecimal (14) 628d
pentadecimal (15) 5071

Historical numeral systems

Babylonian (base 60)
𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹𒁹𒁹 𒁹
Egyptian hieroglyphic
𓂍𓆼𓆼𓆼𓆼𓆼𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺
Greek (Milesian)
͵ιϛϡπαʹ
Mayan (base 20)
𝋢·𝋢·𝋩·𝋡
Chinese
一萬六千九百八十一
Chinese (financial)
壹萬陸仟玖佰捌拾壹
In other modern scripts
Eastern Arabic ١٦٩٨١ Devanagari १६९८१ Bengali ১৬৯৮১ Tamil ௧௬௯௮௧ Thai ๑๖๙๘๑ Tibetan ༡༦༩༨༡ Khmer ១៦៩៨១ Lao ໑໖໙໘໑ Burmese ၁၆၉၈၁

Digit at this position in famous constants

π — Pi (π)
Digit 16,981 = 4
e — Euler's number (e)
Digit 16,981 = 8
φ — Golden ratio (φ)
Digit 16,981 = 0
√2 — Pythagoras's (√2)
Digit 16,981 = 8
ln 2 — Natural log of 2
Digit 16,981 = 6
γ — Euler-Mascheroni (γ)
Digit 16,981 = 0

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 16,979 (gap of 2)
  • Next prime: 16,987 (gap of 6)

Pair status: twin with 16979, sexy with 16987.

Unicode codepoint
CJK Unified Ideograph-4255
U+4255
Other letter (Lo)

UTF-8 encoding: E4 89 95 (3 bytes).

Hex color
#004255
RGB(0, 66, 85)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.66.85.

Address
0.0.66.85
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.66.85

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

Position in π

The digit sequence 16981 first appears in π at position 160,010 of the decimal expansion (the 160,010ordinal-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.