649
649 is a composite number, odd, a calendar year.
649 (six hundred forty-nine) is an odd 3-digit number. It is a composite number with 4 divisors, and factors as 11 × 59. Written other ways, in Roman numerals it is DCXLIX and in binary, 1010001001.
Interestingness
Historical context — 649 AD
Calendar year
Year 649 (DCXLIX) was a common year starting on Thursday of the Julian calendar.
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Historical context — 649 BC
Calendar year
The year 649 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
-
Monday
January 1, 649
- Ended on
-
Monday
December 31, 649
- Friday the 13ths
-
2
2 Friday the 13ths this year.
- Decade
-
640s
640–649
- Century
-
7th century
601–700
- Millennium
-
1st millennium
1–1000
- Years ago
-
1,377
1377 years before 2026.
In other calendars
- Hebrew
-
4409 / 4410 AM
Rosh Hashanah falls in September/October.
- Islamic Hijri
-
28 / 29 AH
Lunar calendar; year spans differ from Gregorian.
- Chinese
-
Year of the zodiac:Earth zodiac:Rooster
Sexagenary cycle position 46 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
1192 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Persian Solar Hijri
-
27 / 28 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
- Ethiopian
-
641 / 642 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
571 / 570 Saka
Indian national calendar; year starts in March.
Properties
Primality
Prime factorization: 11 × 59
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√649 = [25; (2, 9, 1, 2, 3, 1, 1, 2, 1, 4, 1, 16, 6, 3, 4, 3, 6, 16, 1, 4, 1, 2, 1, 1, …)]
Period length 30 — the block in parentheses repeats forever.
Representations
- In words
- six hundred forty-nine
- Ordinal
- 649th
- Roman numeral
- DCXLIX
- Binary
- 1010001001
- Octal
- 1211
- Hexadecimal
- 0x289
- Base64
- Aok=
- One's complement
- 64,886 (16-bit)
- Scientific notation
- 6.49 × 10²
- As a duration
- 649 s = 10 minutes, 49 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒌋 𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- χμθʹ
- Mayan (base 20)
- 𝋡·𝋬·𝋩
- Chinese
- 六百四十九
- Chinese (financial)
- 陸佰肆拾玖
Digit at this position in famous constants
- π — Pi (π)
- Digit 649 = 8
- e — Euler's number (e)
- Digit 649 = 4
- φ — Golden ratio (φ)
- Digit 649 = 1
- √2 — Pythagoras's (√2)
- Digit 649 = 2
- ln 2 — Natural log of 2
- Digit 649 = 4
- γ — Euler-Mascheroni (γ)
- Digit 649 = 9
Also seen as
UTF-8 encoding: CA 89 (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.2.137.
- Address
- 0.0.2.137
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.2.137
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The number 649 is an active NANP area code (North American Numbering Plan).
- Primary area
- Statewide
- Region
- Turks and Caicos Islands
- Country
- Turks and Caicos Islands
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, 649 Hz is closest to:
- Concert pitch (A4 = 440 Hz): E5 (659.3 Hz, -27¢)
- Scientific pitch (C4 = 256 Hz): E5 (645.1 Hz, +10¢)
- Baroque pitch (A4 = 415 Hz): F5 (658.8 Hz, -26¢)
Related reading
- Egyptian hieroglyphic numerals — Seven hieroglyphs for every power of ten, from a single stroke to a million.