2400
2,400 bits per second was the modem speed at which downloading a photograph became conceivable.
- Even
- Composite
Where 2400 fits
Why 2400 is special
It also became the standard rate for early mobile data, and the same figure appears in industrial control systems that have never been updated.
Same number, different meanings
How 2400 is understood across different contexts — never implying one meaning because of another.
- Mathematics
It also became the standard rate for early mobile data, and the same figure appears in industrial control systems that have never been updated.
- Technology & computing
The start of the main Wi-Fi and Bluetooth band is 2400 megahertz (worldwide, ITU Region-dependent). The 2.4 GHz band is shared by Wi-Fi, Bluetooth, microwave ovens and much else, which is why it is congested.
- Science
The Great Oxidation Event around 2,400 million years ago followed the spread of oxygenic photosynthesis. Free oxygen was toxic to much existing life, and the resulting change is recorded in banded iron formations.
2400 is part of
Factors & digit properties
- Divisors (36)
- 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 25, 30, 32, 40, 48, 50, 60, 75, 80, 96, 100, 120, 150, 160, 200, 240, 300, 400, 480, 600, 800, 1200, 2400
- Prime factorisation
- 2^5 × 3 × 5^2
- Digit sum
- 6
- Digital root
- 6
Representations
- Decimal
- 2400
- Scientific notation
- 2.400 × 10^3
Roman numerals
M M C D
MMCD uses the subtractive pair CD: a hundred before five hundred — five hundred minus a hundred.
Binary
1 0 0 1 0 1 1 0 0 0 0 0
1 × 2,048 + 0 × 1,024 + 0 × 512 + 1 × 256 + 0 × 128 + 1 × 64 + 1 × 32 + 0 × 16 + 0 × 8 + 0 × 4 + 0 × 2 + 0 × 1 = 2,400
Octal
4 5 4 0
4 × 512 + 5 × 64 + 4 × 8 + 0 × 1 = 2,400
Hexadecimal
9 6 0
9 × 256 + 6 × 16 + 0 × 1 = 2,400
Read as powers of two: 2,048 + 256 + 64 + 32 = 2,400.
In historical numeral systems
Egyptian
2 lotuses, 4 coils of rope
2 × 1,000 + 4 × 100 = 2,400. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
4 corner wedges (sixties place), empty units place
40 × 60 + 0 = 2400. Places are separated by a space on the tablet, with the higher place written first. The second place is empty, and this is precisely the case the early system could not write unambiguously — the same wedges alone would also read as 1.
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
2400 appears in Numbers in radio and communications, the topic covering numbers that carry a documented radio or communications fact.
1,200 bits per second made an interactive terminal session tolerable and 2,400 doubled it. 2,400 still appears as a default in industrial control equipment decades later.
View 1200 →Numbers Around Us
- appears inRadio and communications
why?
Strength 0.50, confidence "high".
Other connections
- developed from1200
why?
Strength 0.50, confidence "high".
Technology & computing
The start of the main Wi-Fi and Bluetooth band is 2400 megahertz (worldwide, ITU Region-dependent). The 2.4 GHz band is shared by Wi-Fi, Bluetooth, microwave ovens and much else, which is why it is congested.
DocumentedTechnology & computingGeography: worldwide, ITU Region-dependent2,400 bps persists as a default in SCADA and industrial control hardware decades after it disappeared from consumer use. Equipment that works is rarely replaced for speed alone.
DocumentedTechnology & computing
Science
The Great Oxidation Event around 2,400 million years ago followed the spread of oxygenic photosynthesis. Free oxygen was toxic to much existing life, and the resulting change is recorded in banded iron formations.
DocumentedScienceGeography: GlobalPeriod: c.2.4 billion years ago
Common questions
Is 2400 a prime number?
No, 2400 is not prime.
What are the factors of 2400?
The factors of 2400 are 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 25, 30, 32, 40, 48, 50, 60, 75, 80, 96, 100, 120, 150, 160, 200, 240, 300, 400, 480, 600, 800, 1200, 2400.
What is 2400 in Roman numerals?
2400 in Roman numerals is MMCD. CD is subtractive: a hundred before five hundred — five hundred minus a hundred. Written additively it would be MMCCCC, 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: 3 reviewer-confirmed records, sourced and reviewed before publication.
Last reviewed: 15 July 2026