1,240
1,240 is a composite number, even, a calendar year.
1,240 (one thousand two hundred forty) is an even 4-digit number. It is a composite number with 16 divisors, and factors as 2³ × 5 × 31. Its proper divisors sum to 1,640, more than the number itself, making it an abundant number. Written other ways, in Roman numerals it is MCCXL and in binary, 10011011000.
Interestingness
Historical context — 1240 AD
Calendar year
Year 1240 (MCCXL) was a leap year starting on Sunday of the Julian calendar.
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Year facts
- Year type
-
Leap year
Divisible by 4 and not by 100; February has 29 days.
- Days in year
- 366
- ISO weeks
- 52
- Started on
-
Sunday
January 1, 1240
- Ended on
-
Monday
December 31, 1240
- Friday the 13ths
-
3
3 Friday the 13ths this year.
- Decade
-
1240s
1240–1249
- Century
-
13th century
1201–1300
- Millennium
-
2nd millennium
1001–2000
- Years ago
-
786
786 years before 2026.
In other calendars
- Hebrew
-
5000 / 5001 AM
Rosh Hashanah falls in September/October.
- Islamic Hijri
-
637 / 638 AH
Lunar calendar; year spans differ from Gregorian.
- Chinese
-
Year of the zodiac:Metal zodiac:Rat
Sexagenary cycle position 37 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
1783 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Persian Solar Hijri
-
618 / 619 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
- Ethiopian
-
1232 / 1233 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
1162 / 1161 Saka
Indian national calendar; year starts in March.
Properties
Primality
Prime factorization: 2 3 × 5 × 31
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√1,240 = [35; (4, 1, 2, 7, 2, 7, 2, 1, 4, 70)]
Period length 10 — the block in parentheses repeats forever.
Representations
- In words
- one thousand two hundred forty
- Ordinal
- 1240th
- Roman numeral
- MCCXL
- Binary
- 10011011000
- Octal
- 2330
- Hexadecimal
- 0x4D8
- Base64
- BNg=
- One's complement
- 64,295 (16-bit)
- Scientific notation
- 1.24 × 10³
- As a duration
- 1,240 s = 20 minutes, 40 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋 𒌋𒌋𒌋𒌋
- Egyptian hieroglyphic
- 𓆼𓍢𓍢𓎆𓎆𓎆𓎆
- Greek (Milesian)
- ͵ασμʹ
- Mayan (base 20)
- 𝋣·𝋢·𝋠
- Chinese
- 一千二百四十
- Chinese (financial)
- 壹仟貳佰肆拾
Digit at this position in famous constants
- π — Pi (π)
- Digit 1,240 = 8
- e — Euler's number (e)
- Digit 1,240 = 6
- φ — Golden ratio (φ)
- Digit 1,240 = 7
- √2 — Pythagoras's (√2)
- Digit 1,240 = 8
- ln 2 — Natural log of 2
- Digit 1,240 = 5
- γ — Euler-Mascheroni (γ)
- Digit 1,240 = 6
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 1240, here are decompositions:
- 3 + 1237 = 1240
- 11 + 1229 = 1240
- 17 + 1223 = 1240
- 23 + 1217 = 1240
- 47 + 1193 = 1240
- 53 + 1187 = 1240
- 59 + 1181 = 1240
- 89 + 1151 = 1240
Showing the first eight; more decompositions exist.
UTF-8 encoding: D3 98 (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.4.216.
- Address
- 0.0.4.216
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.4.216
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 1,240 Hz is closest to:
- Concert pitch (A4 = 440 Hz): D♯6 (1244.5 Hz, -6¢)
- Scientific pitch (C4 = 256 Hz): D♯6 (1217.7 Hz, +31¢)
- Baroque pitch (A4 = 415 Hz): E6 (1243.6 Hz, -5¢)
The digit sequence 1240 first appears in π at position 22,031 of the decimal expansion (the 22,031ordinal-suffix:st digit after the integer 3).
Search range: the first 1,000,000 fractional digits of π. Any 6-digit-or-shorter string is virtually guaranteed to appear in there — the more interesting signal is the position.
Related reading
- Egyptian hieroglyphic numerals — Seven hieroglyphs for every power of ten, from a single stroke to a million.