158
158 is a composite number, even, a calendar year.
158 (one hundred fifty-eight) is an even 3-digit number. It is a composite number with 4 divisors, and factors as 2 × 79. Written other ways, in Roman numerals it is CLVIII and in binary, 10011110.
Interestingness
Historical context — 158 AD
Calendar year
Year 158 (CLVIII) was a common year starting on Saturday of the Julian calendar.
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Historical context — 158 BC
Calendar year
The Year 158 BC was a year of the pre-Julian Roman calendar.
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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
-
Sunday
January 1, 158
- Ended on
-
Sunday
December 31, 158
- Friday the 13ths
-
2
2 Friday the 13ths this year.
- Decade
-
150s
150–159
- Century
-
2nd century
101–200
- Millennium
-
1st millennium
1–1000
- Years ago
-
1,868
1868 years before 2026.
In other calendars
- Hebrew
-
3918 / 3919 AM
Rosh Hashanah falls in September/October.
- Chinese
-
Year of the zodiac:Earth zodiac:Dog
Sexagenary cycle position 35 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
701 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Ethiopian
-
150 / 151 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
80 / 79 Saka
Indian national calendar; year starts in March.
Properties
Primality
Prime factorization: 2 × 79
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√158 = [12; (1, 1, 3, 12, 3, 1, 1, 24)]
Period length 8 — the block in parentheses repeats forever.
Representations
- In words
- one hundred fifty-eight
- Ordinal
- 158th
- Roman numeral
- CLVIII
- Binary
- 10011110
- Octal
- 236
- Hexadecimal
- 0x9E
- Base64
- ng==
- One's complement
- 97 (8-bit)
- Scientific notation
- 1.58 × 10²
- As a duration
- 158 s = 2 minutes, 38 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹 𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓍢𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ρνηʹ
- Mayan (base 20)
- 𝋧·𝋲
- Chinese
- 一百五十八
- Chinese (financial)
- 壹佰伍拾捌
Digit at this position in famous constants
- π — Pi (π)
- Digit 158 = 4
- e — Euler's number (e)
- Digit 158 = 7
- φ — Golden ratio (φ)
- Digit 158 = 4
- √2 — Pythagoras's (√2)
- Digit 158 = 4
- ln 2 — Natural log of 2
- Digit 158 = 9
- γ — Euler-Mascheroni (γ)
- Digit 158 = 2
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 158, here are decompositions:
- 7 + 151 = 158
- 19 + 139 = 158
- 31 + 127 = 158
- 61 + 97 = 158
- 79 + 79 = 158
UTF-8 encoding: C2 9E (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.158.
- Address
- 0.0.0.158
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.0.158
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 158 Hz is closest to:
- Concert pitch (A4 = 440 Hz): D♯3 (155.6 Hz, +27¢)
- Scientific pitch (C4 = 256 Hz): E3 (161.3 Hz, -35¢)
- Baroque pitch (A4 = 415 Hz): E3 (155.4 Hz, +28¢)
Related reading
- Mayan numerals — Vigesimal dots-and-bars with a shell zero — one of the earliest true zeros.