168
168 is a composite number, even, a calendar year.
168 (one hundred sixty-eight) is an even 3-digit number. It is a composite number with 16 divisors, and factors as 2³ × 3 × 7. Its proper divisors sum to 312, more than the number itself, making it an abundant number. Written other ways, in Roman numerals it is CLXVIII and in binary, 10101000.
Interestingness
Historical context — 168 AD
Calendar year
Year 168 (CLXVIII) was a leap year starting on Thursday of the Julian calendar.
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Notable events — 168 BC
- Jun 22 Rome decisively defeats Macedon at Pydna.
Events compiled from Wikipedia ↗ · Licensed CC BY-SA 4.0
Year facts
- Year type
-
Leap year
Divisible by 4 and not by 100; February has 29 days.
- Days in year
- 366
- ISO weeks
- 52
- Started on
-
Friday
January 1, 168
- Ended on
-
Saturday
December 31, 168
- Friday the 13ths
-
1
One Friday the 13th this year.
- Decade
-
160s
160–169
- Century
-
2nd century
101–200
- Millennium
-
1st millennium
1–1000
- Years ago
-
1,858
1858 years before 2026.
In other calendars
- Hebrew
-
3928 / 3929 AM
Rosh Hashanah falls in September/October.
- Chinese
-
Year of the zodiac:Earth zodiac:Monkey
Sexagenary cycle position 45 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
711 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Ethiopian
-
160 / 161 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
90 / 89 Saka
Indian national calendar; year starts in March.
Properties
- Parity
- Even
- Digit count
- 3
- Digit sum
- 15
- Digit product
- 48
- Digital root
- 6
- Palindrome
- No
- Bit width
- 8 bits
- Reversed
- 861
- Flips to (rotate 180°)
- 891
- Recamán's sequence
- a(331) = 168
- Square (n²)
- 28,224
- Cube (n³)
- 4,741,632
- Divisor count
- 16
- σ(n) — sum of divisors
- 480
- φ(n) — Euler's totient
- 48
- Sum of prime factors
- 16
Primality
Prime factorization: 2 3 × 3 × 7
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√168 = [12; (1, 24)]
Period length 2 — the block in parentheses repeats forever.
Representations
- In words
- one hundred sixty-eight
- Ordinal
- 168th
- Roman numeral
- CLXVIII
- Binary
- 10101000
- Octal
- 250
- Hexadecimal
- 0xA8
- Base64
- qA==
- One's complement
- 87 (8-bit)
- Scientific notation
- 1.68 × 10²
- As a duration
- 168 s = 2 minutes, 48 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹 𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ρξηʹ
- Mayan (base 20)
- 𝋨·𝋨
- Chinese
- 一百六十八
- Chinese (financial)
- 壹佰陸拾捌
Digit at this position in famous constants
- π — Pi (π)
- Digit 168 = 0
- e — Euler's number (e)
- Digit 168 = 2
- φ — Golden ratio (φ)
- Digit 168 = 9
- √2 — Pythagoras's (√2)
- Digit 168 = 2
- ln 2 — Natural log of 2
- Digit 168 = 2
- γ — Euler-Mascheroni (γ)
- Digit 168 = 4
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 168, here are decompositions:
- 5 + 163 = 168
- 11 + 157 = 168
- 17 + 151 = 168
- 19 + 149 = 168
- 29 + 139 = 168
- 31 + 137 = 168
- 37 + 131 = 168
- 41 + 127 = 168
Showing the first eight; more decompositions exist.
UTF-8 encoding: C2 A8 (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.168.
- Address
- 0.0.0.168
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.0.168
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 168 Hz is closest to:
- Concert pitch (A4 = 440 Hz): E3 (164.8 Hz, +33¢)
- Scientific pitch (C4 = 256 Hz): F3 (170.9 Hz, -29¢)
- Baroque pitch (A4 = 415 Hz): F3 (164.7 Hz, +34¢)
Related reading
- Babylonian numerals — The base-60 cuneiform system that gave us 60 minutes, 60 seconds, and 360°.