Number

172

172 is a composite number, even, a calendar year.

Deficient Number Evil Number Recamán's Sequence Year

Historical context — 172 AD

Calendar year

Year 172 (CLXXII) was a leap year starting on Tuesday of the Julian calendar.

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Historical context — 172 BC

Calendar year

Year 172 BC was a year of the pre-Julian Roman calendar.

Excerpt from Wikipedia (en) ↗ · Licensed CC BY-SA 4.0 · English fallback Read the full article on Wikipedia →

Year facts

Year type: Leap year
Divisible by 4 and not by 100; February has 29 days.
Days in year: 366
ISO weeks: 53
Long year: contains 53 ISO weeks.
Started on: Wednesday
January 1, 172
Ended on: Thursday
December 31, 172
Friday the 13ths: 2
2 Friday the 13ths this year.
Decade: 170s
170–179
Century: 2nd century
101–200
Millennium: 1st millennium
1–1000
Years ago: 1,854
1854 years before 2026.

In other calendars

Hebrew: 3932 / 3933 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Water zodiac:Rat
Sexagenary cycle position 49 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 715 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 164 / 165 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 94 / 93 Saka
Indian national calendar; year starts in March.

Properties

Parity: Even
Digit count: 3
Digit sum: 10
Digit product: 14
Digital root: 1
Palindrome: No
Bit width: 8 bits
Reversed: 271
Recamán's sequence: a(323) = 172
Square (n²): 29,584
Cube (n³): 5,088,448
Divisor count: 6
σ(n) — sum of divisors: 308
φ(n) — Euler's totient: 84
Sum of prime factors: 47

Primality

Prime factorization: 2 ² × 43

Nearest primes: 167 (−5) · 173 (+1)

Divisors & multiples

All divisors (6)

1 · 2 · 4 · 43 · 86 (half) · 172

Aliquot sum (sum of proper divisors): 136

Factor pairs (a × b = 172)

1 × 172

2 × 86

4 × 43

First multiples

172 · 344 (double) · 516 · 688 · 860 · 1,032 · 1,204 · 1,376 · 1,548 · 1,720

Sums & aliquot sequence

As consecutive integers: 18 + 19 + … + 25

Aliquot sequence: 172 → 136 → 134 → 70 → 74 → 40 → 50 → 43 → 1 → 0 — terminates at zero

Representations

In words: one hundred seventy-two
Ordinal: 172nd
Roman numeral: CLXXII
Binary: 10101100
Octal: 254
Hexadecimal: 0xAC
Base64: rA==
One's complement: 83 (8-bit)

In other bases

ternary (3) 20101

quaternary (4) 2230

quinary (5) 1142

senary (6) 444

septenary (7) 334

nonary (9) 211

undecimal (11) 147

duodecimal (12) 124

tridecimal (13) 103

tetradecimal (14) c4

pentadecimal (15) b7

Historical numeral systems

Babylonian (base 60): 𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹
Egyptian hieroglyphic: 𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺
Greek (Milesian): ροβʹ
Mayan (base 20): 𝋨·𝋬
Chinese: 一百七十二
Chinese (financial): 壹佰柒拾貳

In other modern scripts

Eastern Arabic ١٧٢ Devanagari १७२ Bengali ১৭২ Tamil ௧௭௨ Thai ๑๗๒ Tibetan ༡༧༢ Khmer ១៧២ Lao ໑໗໒ Burmese ၁၇၂

Digit at this position in famous constants

π — Pi (π): Digit 172 = 8
e — Euler's number (e): Digit 172 = 3
φ — Golden ratio (φ): Digit 172 = 9
√2 — Pythagoras's (√2): Digit 172 = 5
ln 2 — Natural log of 2: Digit 172 = 1
γ — Euler-Mascheroni (γ): Digit 172 = 7

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 172, here are decompositions:

5 + 167 = 172
23 + 149 = 172
41 + 131 = 172
59 + 113 = 172
71 + 101 = 172
83 + 89 = 172

Unicode codepoint

Not Sign

U+00AC

Math symbol (Sm)

UTF-8 encoding: C2 AC (2 bytes).

Lookup U+00AC on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#0000AC

RGB(0, 0, 172)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.172.

Address: 0.0.0.172
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.0.172

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