1,729
1,729 is a composite number, odd, a calendar year.
1729 is the famous taxicab number, the smallest number expressible as the sum of two positive cubes in two different ways:
\(1729 = 1^3 + 12^3 = 9^3 + 10^3\)
The story comes from G. H. Hardy visiting the ailing Ramanujan in hospital. Hardy remarked that he had arrived in cab number 1729, which seemed rather a dull number. Ramanujan immediately replied that, on the contrary, it was a very interesting number — the smallest expressible as the sum of two cubes in two different ways.
Notable events — 1729 AD
- Nov 9 Spain, France, and Britain sign the Treaty of Seville.
- May 20 Frederick the Great's flute lessons begin.
- Undated Bach composes the Brandenburg Concertos (collected and dated 1721, presented across years).
Events compiled from Wikipedia ↗ · Licensed CC BY-SA 4.0
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
-
Saturday
January 1, 1729
- Ended on
-
Saturday
December 31, 1729
- Friday the 13ths
-
1
One Friday the 13th this year.
- Easter Sunday
-
April 17
Sunday, April 17, 1729
- Decade
-
1720s
1720–1729
- Century
-
18th century
1701–1800
- Millennium
-
2nd millennium
1001–2000
- Years ago
-
297
297 years before 2026.
In other calendars
- Hebrew
-
5489 / 5490 AM
Rosh Hashanah falls in September/October.
- Islamic Hijri
-
1141 / 1142 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
-
2272 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Persian Solar Hijri
-
1107 / 1108 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
- Ethiopian
-
1721 / 1722 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
1651 / 1650 Saka
Indian national calendar; year starts in March.
Properties
- Parity
- Odd
- Digit count
- 4
- Digit sum
- 19
- Digit product
- 126
- Digital root
- 1
- Palindrome
- No
- Bit width
- 11 bits
- Reversed
- 9,271
- Recamán's sequence
- a(1,198) = 1,729
- Square (n²)
- 2,989,441
- Cube (n³)
- 5,168,743,489
- Divisor count
- 8
- σ(n) — sum of divisors
- 2,240
- φ(n) — Euler's totient
- 1,296
- Sum of prime factors
- 39
Primality
Prime factorization: 7 × 13 × 19
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- one thousand seven hundred twenty-nine
- Ordinal
- 1729th
- Roman numeral
- MDCCXXIX
- Binary
- 11011000001
- Octal
- 3301
- Hexadecimal
- 0x6C1
- Base64
- BsE=
- One's complement
- 63,806 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ͵αψκθʹ
- Mayan (base 20)
- 𝋤·𝋦·𝋩
- Chinese
- 一千七百二十九
- Chinese (financial)
- 壹仟柒佰貳拾玖
Digit at this position in famous constants
- π — Pi (π)
- Digit 1,729 = 2
- e — Euler's number (e)
- Digit 1,729 = 7
- φ — Golden ratio (φ)
- Digit 1,729 = 6
- √2 — Pythagoras's (√2)
- Digit 1,729 = 3
- ln 2 — Natural log of 2
- Digit 1,729 = 7
- γ — Euler-Mascheroni (γ)
- Digit 1,729 = 5
Also seen as
UTF-8 encoding: DB 81 (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.6.193.
- Address
- 0.0.6.193
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.6.193
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 1729 first appears in π at position 8,042 of the decimal expansion (the 8,042ordinal-suffix:nd 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.