Numberwise

1720

1720 is the year of the South Sea Bubble.

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Where 1720 fits

Where 1720 fits: Mathematics, History, Related numbersMathematics: Harshad (Niven) number. History: Historical years. Related numbers: 1637, 1694.MathematicsHarshad (Niven) numberHistoryHistorical yearsRelated numbers163716941720
1720 connects to 3 worlds: mathematics, history, related numbers.

Why 1720 is special

A company with no meaningful trade drove its own share price up tenfold and collapsed. Isaac Newton lost a large sum and is said to have remarked that he could calculate the motions of heavenly bodies but not the madness of people.

1720 connects to:

  • historical years appears in
  • 1637 contrasts with
  • 1694 is associated with

Same number, different meanings

How 1720 is understood across different contexts — never implying one meaning because of another.

1720 is part of

Factors & digit properties

Divisors (16)
1, 2, 4, 5, 8, 10, 20, 40, 43, 86, 172, 215, 344, 430, 860, 1720
Prime factorisation
2^3 × 5 × 43
Digit sum
10
Digital root
1

Representations

Decimal
1720
Scientific notation
1.720 × 10^3

Roman numerals

M D C C X X

Binary

1 1 0 1 0 1 1 1 0 0 0

1 × 1,024 + 1 × 512 + 0 × 256 + 1 × 128 + 0 × 64 + 1 × 32 + 1 × 16 + 1 × 8 + 0 × 4 + 0 × 2 + 0 × 1 = 1,720

Octal

3 2 7 0

3 × 512 + 2 × 64 + 7 × 8 + 0 × 1 = 1,720

Hexadecimal

6 b 8

6 × 256 + b × 16 + 8 × 1 = 1,720

Read as powers of two: 1,024 + 512 + 128 + 32 + 16 + 8 = 1,720.

In historical numeral systems

Egyptian

1 lotus, 7 coils of rope, 2 hobbles

1 × 1,000 + 7 × 100 + 2 × 10 = 1,720. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.

Babylonian

2 corner wedges + 8 vertical wedges (sixties place), 4 corner wedges (units place)

28 × 60 + 40 = 1720. Places are separated by a space on the tablet, with the higher place written first.

Systems that simply cannot reach this value are left out. Where a script needs a font most readers do not have, the reading is given instead of the glyphs — see number systems for each system in full.

Other mathematical patterns

  • Abundant number
  • Harshad (Niven) number

Related numbers & connections

Documented appearance
1720 is a year in the 18th century, in the 1720s.

1720 is a year in the 18th century, in the 1720s.

Connection
The South Sea Bubble and tulip mania are the two standard historical bubbles. Modern research suggests the tulip episode was far smaller than its reputation, while the South Sea collapse was genuinely severe.

The South Sea Bubble and tulip mania are the two standard historical bubbles. Modern research suggests the tulip episode was far smaller than its reputation, while the South Sea collapse was genuinely severe.

View 1637

Numbers Around Us

  • appears inHistorical years
    why?

    Strength 0.50, confidence "high".

Other connections

  • contrasts with1637
    why?

    Strength 0.50, confidence "high".

  • is associated with1694
    why?

    Strength 0.50, confidence "high".

How is 1720 connected to another number? →

History

  • In 1720, the South Sea Bubble collapsed, ruining investors including Isaac Newton and prompting the first British company legislation (Great Britain).

    DocumentedHistoryGeography: Great BritainPeriod: 1720

Finance & economics

  • The South Sea Company's business was assuming government debt, not trading. Its share price rose roughly tenfold on expectation alone and collapsed within months, taking down investors including Newton.

    DocumentedFinance & economicsGeography: BritainPeriod: 1720

Common questions

Is 1720 a prime number?

No, 1720 is not prime.

What are the factors of 1720?

The factors of 1720 are 1, 2, 4, 5, 8, 10, 20, 40, 43, 86, 172, 215, 344, 430, 860, 1720.

What is 1720 in Roman numerals?

1720 in Roman numerals is MDCCXX.

About this page's data

Mathematical facts:computed directly from the number's value — nothing to source or verify externally.

Contextual records: 2 reviewer-confirmed records, sourced and reviewed before publication.

Last reviewed: 15 July 2026