1597
1,597 is a Fibonacci number and a prime.
Where 1597 fits
Why 1597 is special
It is the seventeenth Fibonacci number, and the largest Fibonacci prime below ten thousand. Only a handful are known at all, and whether the list ends is unresolved despite the sequence itself being completely understood.
1597 connects to:
- 233 — is a multiple of
- historical years — appears in
- fibonacci sequence — appears in
1597 is part of
Factors & digit properties
- Divisors (2)
- 1, 1597
- Prime factorisation
- 1597
- Digit sum
- 22
- Digital root
- 4
Representations
- Decimal
- 1597
- Scientific notation
- 1.597 × 10^3
Roman numerals
M D X C V I I
MDXCVII uses the subtractive pair XC: ten before a hundred — a hundred minus ten.
Binary
1 1 0 0 0 1 1 1 1 0 1
1 × 1,024 + 1 × 512 + 0 × 256 + 0 × 128 + 0 × 64 + 1 × 32 + 1 × 16 + 1 × 8 + 1 × 4 + 0 × 2 + 1 × 1 = 1,597
Octal
3 0 7 5
3 × 512 + 0 × 64 + 7 × 8 + 5 × 1 = 1,597
Hexadecimal
6 3 d
6 × 256 + 3 × 16 + d × 1 = 1,597
Read as powers of two: 1,024 + 512 + 32 + 16 + 8 + 4 + 1 = 1,597.
In historical numeral systems
Egyptian
1 lotus, 5 coils of rope, 9 hobbles, 7 strokes
1 × 1,000 + 5 × 100 + 9 × 10 + 7 × 1 = 1,597. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
2 corner wedges + 6 vertical wedges (sixties place), 3 corner wedges + 7 vertical wedges (units place)
26 × 60 + 37 = 1597. 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
- Deficient number
- Lucky number (mathematical sieve)
Related numbers & connections
Both are Fibonacci primes, four places apart in the sequence. 1,597 divided by 233 is close to the golden ratio raised to the fourth power, which is what Fibonacci ratios converge on.
View 233 →1597 is a year in the 16th century, in the 1590s.
Mathematically related
- is a multiple of233
why?
Strength 0.50, confidence "high".
Numbers Around Us
- appears inHistorical years
why?
Strength 0.50, confidence "high".
- appears inFibonacci sequence
why?
Strength 0.50, confidence "high".
History
In 1597, John Gerard's Herball catalogued plants for English readers and remained in use for generations (England).
DocumentedHistoryGeography: EnglandPeriod: 1597
Mathematics
1,597 is the seventeenth Fibonacci number, prime, and the last Fibonacci prime under ten thousand. Only a few dozen are known in total despite the sequence being completely understood, which is the gap that makes the open question interesting.
DocumentedMathematics
Common questions
Is 1597 a prime number?
Yes, 1597 is prime — it has exactly two positive divisors: 1 and itself.
What are the factors of 1597?
The factors of 1597 are 1, 1597.
What is 1597 in Roman numerals?
1597 in Roman numerals is MDXCVII. XC is subtractive: ten before a hundred — a hundred minus ten. Written additively it would be MDLXXXXVII, which Roman inscriptions used freely — the strict subtractive form is a later convention.
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