79
79 is a prime, odd, a calendar year.
79 (seventy-nine) is an odd 2-digit number. It is a prime number — divisible only by 1 and itself. Written other ways, in Roman numerals it is LXXIX and in binary, 1001111.
Interestingness
Notable events — 79 AD
- Jun 23 Emperor Vespasian dies; his son Titus succeeds him.
- Aug 24 Mount Vesuvius erupts, burying Pompeii and Herculaneum.
- Undated Pliny the Elder dies during the Vesuvius evacuation.
- Undated The Roman fort Deva Victrix — modern Chester — is founded.
Events compiled from Wikipedia ↗ · Licensed CC BY-SA 4.0
Historical context — 79 BC
Calendar year
Year 79 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
-
Sunday
January 1, 79
- Ended on
-
Sunday
December 31, 79
- Friday the 13ths
-
2
2 Friday the 13ths this year.
- Decade
-
70s
70–79
- Century
-
1st century
1–100
- Millennium
-
1st millennium
1–1000
- Years ago
-
1,947
1947 years before 2026.
In other calendars
- Hebrew
-
3839 / 3840 AM
Rosh Hashanah falls in September/October.
- Chinese
-
Year of the zodiac:Earth zodiac:Rabbit
Sexagenary cycle position 16 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
622 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Ethiopian
-
71 / 72 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
1 / 0 Saka
Indian national calendar; year starts in March.
Properties
Primality
79 is prime. It has exactly two divisors: 1 and itself.
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√79 = [8; (1, 7, 1, 16)]
Period length 4 — the block in parentheses repeats forever.
Representations
- In words
- seventy-nine
- Ordinal
- 79th
- Roman numeral
- LXXIX
- Binary
- 1001111
- Octal
- 117
- Hexadecimal
- 0x4F
- Base64
- Tw==
- One's complement
- 176 (8-bit)
- Scientific notation
- 7.9 × 10¹
- As a duration
- 79 s = 1 minute, 19 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹 𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- οθʹ
- Mayan (base 20)
- 𝋣·𝋳
- Chinese
- 七十九
- Chinese (financial)
- 柒拾玖
Digit at this position in famous constants
- π — Pi (π)
- Digit 79 = 8
- e — Euler's number (e)
- Digit 79 = 7
- φ — Golden ratio (φ)
- Digit 79 = 2
- √2 — Pythagoras's (√2)
- Digit 79 = 7
- ln 2 — Natural log of 2
- Digit 79 = 4
- γ — Euler-Mascheroni (γ)
- Digit 79 = 4
Also seen as
As an ASCII codepoint, 79 is O. Printable ASCII character O.
As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.79.
- Address
- 0.0.0.79
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.0.79
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Matches numbered highway designation:
- I-79 — Charleston, WV to Erie, PA.
Heard as a frequency, 79 Hz is closest to:
- Concert pitch (A4 = 440 Hz): D♯2 (77.8 Hz, +27¢)
- Scientific pitch (C4 = 256 Hz): E2 (80.6 Hz, -35¢)
- Baroque pitch (A4 = 415 Hz): E2 (77.7 Hz, +28¢)
As a MIDI note number, 79 is G5 (784 Hz at concert pitch).
Related reading
- Prime numbers — The building blocks of arithmetic: what primes are, why they matter, and how we find them.
- Egyptian hieroglyphic numerals — Seven hieroglyphs for every power of ten, from a single stroke to a million.