Number

72,161

72,161 is a prime, odd.

72,161 (seventy-two thousand one hundred sixty-one) is an odd 5-digit number. It is a prime number — divisible only by 1 and itself. Written other ways, in hexadecimal, 0x119E1.

Arithmetic Number Cube-Free Deficient Number Emirp Evil Number Happy Number Prime Pythagorean Prime Recamán's Sequence Sexy Prime Sophie Germain Prime Squarefree

Interestingness

★ ★ ★ ★ ★

10 notable facts · grade A

72,149 72,150 72,151 72,152 72,153 72,154 72,155 72,156 72,157 72,158 72,159 72,160 72,161 72,162 72,163 72,164 72,165 72,166 72,167 72,168 72,169 72,170 72,171 72,172 72,173

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Properties

Parity: Odd
Digit count: 5
Digit sum: 17
Digit product: 84
Digital root: 8
Palindrome: No
Bit width: 17 bits
Reversed: 16,127
Recamán's sequence: a(127,277) = 72,161
Square (n²): 5,207,209,921
Cube (n³): 375,757,475,109,281
Divisor count: 2
σ(n) — sum of divisors: 72,162
φ(n) — Euler's totient: 72,160

Primality

72,161 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)

1 · 72161

Aliquot sum (sum of proper divisors): 1

Factor pairs (a × b = 72,161)

1 × 72161

First multiples

72,161 · 144,322 (double) · 216,483 · 288,644 · 360,805 · 432,966 · 505,127 · 577,288 · 649,449 · 721,610

Sums & aliquot sequence

As a sum of two squares: 44² + 265²

As consecutive integers: 36,080 + 36,081

Continued fraction of √n

√72,161 = [268; (1, 1, 1, 2, 4, 1, 5, 3, 2, 3, 3, 1, 1, 1, 13, 1, 7, 2, 6, 4, 13, 5, 4, 9, …)]

Representations

In words: seventy-two thousand one hundred sixty-one
Ordinal: 72161st
Binary: 10001100111100001
Octal: 214741
Hexadecimal: 0x119E1
Base64: ARnh
One's complement: 4,294,895,134 (32-bit)
Scientific notation: 7.2161 × 10⁴
As a duration: 72,161 s = 20 hours, 2 minutes, 41 seconds

In other bases

ternary (3) 10122222122

quaternary (4) 101213201

quinary (5) 4302121

senary (6) 1314025

septenary (7) 420245

nonary (9) 118878

undecimal (11) 4a241

duodecimal (12) 35915

tridecimal (13) 26acb

tetradecimal (14) 1c425

pentadecimal (15) 165ab

As an angle

72,161° = 200 × 360° + 161°

161° ≈ 2.81 rad

Compass bearing: SSE (south-southeast)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋𒌋 𒁹𒁹 𒌋𒌋𒌋𒌋𒁹
Egyptian hieroglyphic: 𓂍𓂍𓂍𓂍𓂍𓂍𓂍𓆼𓆼𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓏺
Greek (Milesian): ͵οβρξαʹ
Mayan (base 20): 𝋩·𝋠·𝋨·𝋡
Chinese: 七萬二千一百六十一
Chinese (financial): 柒萬貳仟壹佰陸拾壹

In other modern scripts

Eastern Arabic ٧٢١٦١ Devanagari ७२१६१ Bengali ৭২১৬১ Tamil ௭௨௧௬௧ Thai ๗๒๑๖๑ Tibetan ༧༢༡༦༡ Khmer ៧២១៦១ Lao ໗໒໑໖໑ Burmese ၇၂၁၆၁

Digit at this position in famous constants

π — Pi (π): Digit 72,161 = 0
e — Euler's number (e): Digit 72,161 = 7
φ — Golden ratio (φ): Digit 72,161 = 8
√2 — Pythagoras's (√2): Digit 72,161 = 7
ln 2 — Natural log of 2: Digit 72,161 = 2
γ — Euler-Mascheroni (γ): Digit 72,161 = 6

Also seen as

Prime neighborhood

Adjacent primes:

Previous prime: 72,139 (gap of 22)
Next prime: 72,167 (gap of 6)

Pair status: sexy with 72167.

Unicode codepoint

𑧡

Nandinagari Sign Avagraha

U+119E1

Other letter (Lo)

UTF-8 encoding: F0 91 A7 A1 (4 bytes).

Lookup U+119E1 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#0119E1

RGB(1, 25, 225)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.1.25.225.

Address: 0.1.25.225
Class: reserved
IPv4-mapped IPv6: ::ffff:0.1.25.225

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

Position in π

The digit sequence 72161 first appears in π at position 144,576 of the decimal expansion (the 144,576ordinal-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 72161 on Pi Search ↗