777
777 refers to the Boeing 777, the world's largest twin-engine jet, and is the classic jackpot symbol on slot machines.
- Odd
- Composite
Where 777 fits
Why 777 is special
777 carries two unrelated modern associations: the Boeing 777, which entered service in 1995 as the largest twin-engined airliner ever built, and the triple-seven jackpot line on slot machines, a gambling convention recognisable well beyond the machines themselves. Mathematically it is 7 × 111.
Same number, different meanings
How 777 is understood across different contexts — never implying one meaning because of another.
- Mathematics
777 carries two unrelated modern associations: the Boeing 777, which entered service in 1995 as the largest twin-engined airliner ever built, and the triple-seven jackpot line on slot machines, a gambling convention recognisable well beyond the machines themselves. Mathematically it is 7 × 111.
- History
Some Christian writing treats 777 as a counterpoint to 666, on the reading that seven denotes completeness. The contrast is an interpretive tradition rather than a statement in the text, which does not mention 777.
- Everyday life
Three sevens is the conventional top payout on a mechanical slot machine, a convention established by early twentieth-century machines and retained on digital ones that have no reels at all.
- Technology & computing
The 777 was the first commercial aircraft designed entirely on computer, with no physical mock-up. Its reliability record is also what made extended twin-engine operations over oceans routine, replacing a rule that had required three or four engines.
- Culture
A line of three sevens is the conventional jackpot symbol on slot machines, a gambling motif recognisable well beyond casinos themselves.
777 is part of
Factors & digit properties
- Divisors (8)
- 1, 3, 7, 21, 37, 111, 259, 777
- Prime factorisation
- 3 × 7 × 37
- Digit sum
- 21
- Digital root
- 3
Representations
- Decimal
- 777
- Scientific notation
- 7.770 × 10^2
Roman numerals
D C C L X X V I I
Binary
1 1 0 0 0 0 1 0 0 1
1 × 512 + 1 × 256 + 0 × 128 + 0 × 64 + 0 × 32 + 0 × 16 + 1 × 8 + 0 × 4 + 0 × 2 + 1 × 1 = 777
Octal
1 4 1 1
1 × 512 + 4 × 64 + 1 × 8 + 1 × 1 = 777
Hexadecimal
3 0 9
3 × 256 + 0 × 16 + 9 × 1 = 777
Read as powers of two: 512 + 256 + 8 + 1 = 777.
In historical numeral systems
Egyptian
7 coils of rope, 7 hobbles, 7 strokes
7 × 100 + 7 × 10 + 7 × 1 = 777. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
1 corner wedge + 2 vertical wedges (sixties place), 5 corner wedges + 7 vertical wedges (units place)
12 × 60 + 57 = 777. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
psi, then omicron, then zeta, marked as a numeral
psi-omicron-zeta + keraia
psi + omicron + zeta written in descending order and added — the letters carry their values wherever they stand, so this is addition, not place value.
Hebrew numerals
tav, then shin, then ayin, then zayin
tav-shin-ayin-zayin
tav (400) + shin (300) + ayin (70) + zayin (7) = 777, written in descending order.
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
- Palindromic number
- Deficient number
- Repdigit
- Harshad (Niven) number
- Lucky number (mathematical sieve)
Related numbers & connections
777 is 7 × 111 — the repdigit structure that makes it read as a triple seven.
View 111 →The 777 was designed entirely on computer; the 787 went further and replaced most of the aluminium with carbon fibre, allowing higher cabin pressure and humidity.
View 787 →History
Some Christian writing treats 777 as a counterpoint to 666, on the reading that seven denotes completeness. The contrast is an interpretive tradition rather than a statement in the text, which does not mention 777.
Widely documentedHistoryCulture: ChristianityGeography: Christian interpretive traditionPeriod: modern
Everyday life
Three sevens is the conventional top payout on a mechanical slot machine, a convention established by early twentieth-century machines and retained on digital ones that have no reels at all.
DocumentedEveryday lifeGeography: United States, then internationalPeriod: 1900s–
Technology & computing
The 777 was the first commercial aircraft designed entirely on computer, with no physical mock-up. Its reliability record is also what made extended twin-engine operations over oceans routine, replacing a rule that had required three or four engines.
DocumentedTechnology & computingThe Boeing 777 entered commercial service in 1995 and is the largest twin-engined airliner ever built, introduced as a more fuel-efficient long-haul alternative to four-engine wide-bodies such as the 747.
DocumentedTechnology & computingPeriod: entered service 1995
Culture
A line of three sevens is the conventional jackpot symbol on slot machines, a gambling motif recognisable well beyond casinos themselves.
Widely documentedCulture
Common questions
Is 777 a prime number?
No, 777 is not prime.
What are the factors of 777?
The factors of 777 are 1, 3, 7, 21, 37, 111, 259, 777.
What is 777 in Roman numerals?
777 in Roman numerals is DCCLXXVII.
About this page's data
Mathematical facts:computed directly from the number's value — nothing to source or verify externally.
Contextual records: 5 reviewer-confirmed records, sourced and reviewed before publication.
Last reviewed: 15 July 2026