505
505 is a composite number, odd, a calendar year.
505 (five hundred five) is an odd 3-digit number. It is a composite number with 4 divisors, and factors as 5 × 101. Its digits read the same forwards and backwards, so it is a palindromic number. Written other ways, in Roman numerals it is DV and in binary, 111111001.
Interestingness
Historical context — 505 AD
Calendar year
Year 505 (DV) was a common year starting on Saturday of the Julian calendar.
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Historical context — 505 BC
Calendar year
The year 505 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
-
53
Long year: contains 53 ISO weeks.
- Started on
-
Thursday
January 1, 505
- Ended on
-
Thursday
December 31, 505
- Friday the 13ths
-
3
3 Friday the 13ths this year.
- Decade
-
500s
500–509
- Century
-
6th century
501–600
- Millennium
-
1st millennium
1–1000
- Years ago
-
1,521
1521 years before 2026.
In other calendars
- Hebrew
-
4265 / 4266 AM
Rosh Hashanah falls in September/October.
- Chinese
-
Year of the zodiac:Wood zodiac:Rooster
Sexagenary cycle position 22 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
1048 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Ethiopian
-
497 / 498 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
427 / 426 Saka
Indian national calendar; year starts in March.
Properties
Primality
Prime factorization: 5 × 101
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√505 = [22; (2, 8, 2, 44)]
Period length 4 — the block in parentheses repeats forever.
Representations
- In words
- five hundred five
- Ordinal
- 505th
- Roman numeral
- DV
- Binary
- 111111001
- Octal
- 771
- Hexadecimal
- 0x1F9
- Base64
- Afk=
- One's complement
- 65,030 (16-bit)
- Scientific notation
- 5.05 × 10²
- As a duration
- 505 s = 8 minutes, 25 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓍢𓍢𓍢𓍢𓍢𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- φεʹ
- Mayan (base 20)
- 𝋡·𝋥·𝋥
- Chinese
- 五百零五
- Chinese (financial)
- 伍佰零伍
Digit at this position in famous constants
- π — Pi (π)
- Digit 505 = 3
- e — Euler's number (e)
- Digit 505 = 6
- φ — Golden ratio (φ)
- Digit 505 = 7
- √2 — Pythagoras's (√2)
- Digit 505 = 8
- ln 2 — Natural log of 2
- Digit 505 = 8
- γ — Euler-Mascheroni (γ)
- Digit 505 = 8
Also seen as
UTF-8 encoding: C7 B9 (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.1.249.
- Address
- 0.0.1.249
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.1.249
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The number 505 is an active NANP area code (North American Numbering Plan).
- Primary area
- Albuquerque / Santa Fe
- Region
- New Mexico
- Country
- United States
Most NANP area codes have multiple overlays in dense regions; the primary area listed is the historic/largest population center for this code.
Heard as a frequency, 505 Hz is closest to:
- Concert pitch (A4 = 440 Hz): B4 (493.9 Hz, +39¢)
- Scientific pitch (C4 = 256 Hz): C5 (512 Hz, -24¢)
- Baroque pitch (A4 = 415 Hz): C5 (493.5 Hz, +40¢)
Related reading
- Egyptian hieroglyphic numerals — Seven hieroglyphs for every power of ten, from a single stroke to a million.