515
515 is a composite number, odd, a calendar year.
515 (five hundred fifteen) is an odd 3-digit number. It is a composite number with 4 divisors, and factors as 5 × 103. Its digits read the same forwards and backwards, so it is a palindromic number. Written other ways, in Roman numerals it is DXV and in binary, 1000000011.
Interestingness
Historical context — 515 AD
Calendar year
Year 515 (DXV) was a common year starting on Thursday of the Julian calendar.
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Historical context — 515 BC
Calendar year
The year 515 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, 515
- Ended on
-
Tuesday
December 31, 515
- Friday the 13ths
-
2
2 Friday the 13ths this year.
- Decade
-
510s
510–519
- Century
-
6th century
501–600
- Millennium
-
1st millennium
1–1000
- Years ago
-
1,511
1511 years before 2026.
In other calendars
- Hebrew
-
4275 / 4276 AM
Rosh Hashanah falls in September/October.
- Chinese
-
Year of the zodiac:Wood zodiac:Goat
Sexagenary cycle position 32 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
1058 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Ethiopian
-
507 / 508 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
437 / 436 Saka
Indian national calendar; year starts in March.
Properties
Primality
Prime factorization: 5 × 103
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√515 = [22; (1, 2, 3, 1, 3, 1, 3, 2, 1, 44)]
Period length 10 — the block in parentheses repeats forever.
Representations
- In words
- five hundred fifteen
- Ordinal
- 515th
- Roman numeral
- DXV
- Binary
- 1000000011
- Octal
- 1003
- Hexadecimal
- 0x203
- Base64
- AgM=
- One's complement
- 65,020 (16-bit)
- Scientific notation
- 5.15 × 10²
- As a duration
- 515 s = 8 minutes, 35 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓍢𓍢𓍢𓍢𓍢𓎆𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- φιεʹ
- Mayan (base 20)
- 𝋡·𝋥·𝋯
- Chinese
- 五百一十五
- Chinese (financial)
- 伍佰壹拾伍
Digit at this position in famous constants
- π — Pi (π)
- Digit 515 = 6
- e — Euler's number (e)
- Digit 515 = 9
- φ — Golden ratio (φ)
- Digit 515 = 7
- √2 — Pythagoras's (√2)
- Digit 515 = 2
- ln 2 — Natural log of 2
- Digit 515 = 9
- γ — Euler-Mascheroni (γ)
- Digit 515 = 5
Also seen as
UTF-8 encoding: C8 83 (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.2.3.
- Address
- 0.0.2.3
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.2.3
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The number 515 is an active NANP area code (North American Numbering Plan).
- Primary area
- Des Moines
- Region
- Iowa
- 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.
Type 515 on a seven-segment calculator, flip it 180°, and the display reads:
SIS
A staple of calculator humor since pocket calculators put digits in front of bored students.
Heard as a frequency, 515 Hz is closest to:
- Concert pitch (A4 = 440 Hz): C5 (523.3 Hz, -28¢)
- Scientific pitch (C4 = 256 Hz): C5 (512 Hz, +10¢)
- Baroque pitch (A4 = 415 Hz): C♯5 (522.9 Hz, -26¢)
Related reading
- Mayan numerals — Vigesimal dots-and-bars with a shell zero — one of the earliest true zeros.