Number

16,661

16,661 is a prime, odd.

Arithmetic Number Chen Prime Cousin Prime Deficient Number Flippable Odious Number Palindrome Pernicious Number Prime Pythagorean Prime Recamán's Sequence Squarefree

Properties

Parity: Odd
Digit count: 5
Digit sum: 20
Digit product: 216
Digital root: 2
Palindrome: Yes
Bit width: 15 bits
Flips to (rotate 180°): 19,991
Recamán's sequence: a(44,637) = 16,661
Square (n²): 277,588,921
Cube (n³): 4,624,909,012,781
Divisor count: 2
σ(n) — sum of divisors: 16,662
φ(n) — Euler's totient: 16,660

Primality

16,661 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)

1 · 16661

Aliquot sum (sum of proper divisors): 1

Factor pairs (a × b = 16,661)

1 × 16661

First multiples

16,661 · 33,322 (double) · 49,983 · 66,644 · 83,305 · 99,966 · 116,627 · 133,288 · 149,949 · 166,610

Sums & aliquot sequence

As a sum of two squares: 50² + 119²

As consecutive integers: 8,330 + 8,331

Representations

In words: sixteen thousand six hundred sixty-one
Ordinal: 16661st
Binary: 100000100010101
Octal: 40425
Hexadecimal: 0x4115
Base64: QRU=
One's complement: 48,874 (16-bit)

In other bases

ternary (3) 211212002

quaternary (4) 10010111

quinary (5) 1013121

senary (6) 205045

septenary (7) 66401

nonary (9) 24762

undecimal (11) 11577

duodecimal (12) 9785

tridecimal (13) 7778

tetradecimal (14) 6101

pentadecimal (15) 4e0b

Historical numeral systems

Babylonian (base 60): 𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹
Egyptian hieroglyphic: 𓂍𓆼𓆼𓆼𓆼𓆼𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓏺
Greek (Milesian): ͵ιϛχξαʹ
Mayan (base 20): 𝋢·𝋡·𝋭·𝋡
Chinese: 一萬六千六百六十一
Chinese (financial): 壹萬陸仟陸佰陸拾壹

In other modern scripts

Eastern Arabic ١٦٦٦١ Devanagari १६६६१ Bengali ১৬৬৬১ Tamil ௧௬௬௬௧ Thai ๑๖๖๖๑ Tibetan ༡༦༦༦༡ Khmer ១៦៦៦១ Lao ໑໖໖໖໑ Burmese ၁၆၆၆၁

Digit at this position in famous constants

π — Pi (π): Digit 16,661 = 4
e — Euler's number (e): Digit 16,661 = 8
φ — Golden ratio (φ): Digit 16,661 = 7
√2 — Pythagoras's (√2): Digit 16,661 = 3
ln 2 — Natural log of 2: Digit 16,661 = 7
γ — Euler-Mascheroni (γ): Digit 16,661 = 0

Also seen as

Prime neighborhood

Adjacent primes:

Previous prime: 16,657 (gap of 4)
Next prime: 16,673 (gap of 12)

Pair status: cousin with 16657.

Unicode codepoint

䄕

CJK Unified Ideograph-4115

U+4115

Other letter (Lo)

UTF-8 encoding: E4 84 95 (3 bytes).

Lookup U+4115 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#004115

RGB(0, 65, 21)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.65.21.

Address: 0.0.65.21
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.65.21

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

Position in π

The digit sequence 16661 first appears in π at position 65,195 of the decimal expansion (the 65,195ordinal-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.

Look up 16661 on Pi Search ↗