173
173 is a prime, odd, a calendar year.
173 (one hundred seventy-three) is an odd 3-digit number. It is a prime number — divisible only by 1 and itself. Written other ways, in Roman numerals it is CLXXIII and in binary, 10101101.
Interestingness
Historical context — 173 AD
Calendar year
Year 173 (CLXXIII) was a common year starting on Thursday of the Julian calendar.
Excerpt from Wikipedia (en) ↗ · Licensed CC BY-SA 4.0 Read the full article on Wikipedia →
Historical context — 173 BC
Calendar year
Year 173 BC was a year of the pre-Julian Roman calendar.
Excerpt from Wikipedia (en) ↗ · Licensed CC BY-SA 4.0 Read the full article on Wikipedia →
Year facts
- Year type
-
Common year
Standard 365-day year; not divisible by 4 (or divisible by 100 but not 400).
- Days in year
- 365
- ISO weeks
- 52
- Started on
-
Friday
January 1, 173
- Ended on
-
Friday
December 31, 173
- Friday the 13ths
-
1
One Friday the 13th this year.
- Decade
-
170s
170–179
- Century
-
2nd century
101–200
- Millennium
-
1st millennium
1–1000
- Years ago
-
1,853
1853 years before 2026.
In other calendars
- Hebrew
-
3933 / 3934 AM
Rosh Hashanah falls in September/October.
- Chinese
-
Year of the zodiac:Water zodiac:Ox
Sexagenary cycle position 50 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
716 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Ethiopian
-
165 / 166 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
95 / 94 Saka
Indian national calendar; year starts in March.
Properties
Primality
173 is prime. It has exactly two divisors: 1 and itself.
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√173 = [13; (6, 1, 1, 6, 26)]
Period length 5 — the block in parentheses repeats forever.
Representations
- In words
- one hundred seventy-three
- Ordinal
- 173rd
- Roman numeral
- CLXXIII
- Binary
- 10101101
- Octal
- 255
- Hexadecimal
- 0xAD
- Base64
- rQ==
- One's complement
- 82 (8-bit)
- Scientific notation
- 1.73 × 10²
- As a duration
- 173 s = 2 minutes, 53 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺
- Greek (Milesian)
- ρογʹ
- Mayan (base 20)
- 𝋨·𝋭
- Chinese
- 一百七十三
- Chinese (financial)
- 壹佰柒拾參
Digit at this position in famous constants
- π — Pi (π)
- Digit 173 = 5
- e — Euler's number (e)
- Digit 173 = 4
- φ — Golden ratio (φ)
- Digit 173 = 5
- √2 — Pythagoras's (√2)
- Digit 173 = 5
- ln 2 — Natural log of 2
- Digit 173 = 4
- γ — Euler-Mascheroni (γ)
- Digit 173 = 3
Also seen as
UTF-8 encoding: C2 AD (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.173.
- Address
- 0.0.0.173
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.0.173
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 173 Hz is closest to:
- Concert pitch (A4 = 440 Hz): F3 (174.6 Hz, -16¢)
- Scientific pitch (C4 = 256 Hz): F3 (170.9 Hz, +22¢)
- Baroque pitch (A4 = 415 Hz): F♯3 (174.5 Hz, -15¢)
Related reading
- Prime numbers — The building blocks of arithmetic: what primes are, why they matter, and how we find them.
- Mayan numerals — Vigesimal dots-and-bars with a shell zero — one of the earliest true zeros.