69
69 is a composite number, odd, a calendar year.
Sixty-nine is a semiprime (3 × 23) and is widely known for its juvenile humor association. It is the only number whose square (4761) and cube (328509) together use every digit 0–9 exactly once.
Historical context — 69 AD
Calendar year
AD 69 (LXIX) was a common year starting on Sunday of the Julian calendar.
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Historical context — 69 BC
Calendar year
Year 69 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
-
Tuesday
January 1, 69
- Ended on
-
Tuesday
December 31, 69
- Friday the 13ths
-
2
2 Friday the 13ths this year.
- Decade
-
60s
60–69
- Century
-
1st century
1–100
- Millennium
-
1st millennium
1–1000
- Years ago
-
1,957
1957 years before 2026.
In other calendars
- Hebrew
-
3829 / 3830 AM
Rosh Hashanah falls in September/October.
- Chinese
-
Year of the zodiac:Earth zodiac:Snake
Sexagenary cycle position 6 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
612 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Ethiopian
-
61 / 62 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
-9 / -10 Saka
Indian national calendar; year starts in March.
Cultural significance
Sourced from Wikipedia (Numerology, Chinese numerology, Gematria, and per-culture articles).
Properties
Primality
Prime factorization: 3 × 23
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- sixty-nine
- Ordinal
- 69th
- Roman numeral
- LXIX
- Binary
- 1000101
- Octal
- 105
- Hexadecimal
- 0x45
- Base64
- RQ==
- One's complement
- 186 (8-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒁹 𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ξθʹ
- Mayan (base 20)
- 𝋣·𝋩
- Chinese
- 六十九
- Chinese (financial)
- 陸拾玖
Digit at this position in famous constants
- π — Pi (π)
- Digit 69 = 1
- e — Euler's number (e)
- Digit 69 = 7
- φ — Golden ratio (φ)
- Digit 69 = 6
- √2 — Pythagoras's (√2)
- Digit 69 = 3
- ln 2 — Natural log of 2
- Digit 69 = 9
- γ — Euler-Mascheroni (γ)
- Digit 69 = 6
Also seen as
As an ASCII codepoint, 69 is E. Printable ASCII character E.
TCP/UDP port 69 is the well-known port for TFTP — Trivial File Transfer Protocol.
As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.69.
- Address
- 0.0.0.69
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.0.69
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Matches numbered highway designation:
- I-69 — Multiple segments: Texas border, Indianapolis to Port Huron, MI.