48
The 48 contiguous US states are all of them except Alaska and Hawaii — the "lower 48". 48 is also highly composite, with ten divisors, and the atomic number of cadmium.
- Even
- Composite
Where 48 fits
Why 48 is special
48's highly divisible mathematical profile (10 divisors) pairs with a specific geographic fact: it's two short of the full 50 US states, excluding Alaska and Hawaii.
Same number, different meanings
How 48 is understood across different contexts — never implying one meaning because of another.
- Mathematics
48's highly divisible mathematical profile (10 divisors) pairs with a specific geographic fact: it's two short of the full 50 US states, excluding Alaska and Hawaii.
- Technology & computing
48,000 samples per second is the standard audio sample rate for film, television and professional recording, where CD audio uses 44,100. The split is historical rather than acoustic: 44.1 kHz was chosen to fit audio onto video tape, while 48 kHz divides cleanly by common video frame rates, which is why the two have never merged.
- Geography
The 48 contiguous United States are the US states located on the North American mainland, excluding Alaska and Hawaii.
- Science
48 is the atomic number of cadmium. Once common in rechargeable NiCd batteries and bright yellow and red pigments, its toxicity has since driven it out of most consumer uses.
48 is part of
Factors & digit properties
- Divisors (10)
- 1, 2, 3, 4, 6, 8, 12, 16, 24, 48
- Prime factorisation
- 2^4 × 3
- Digit sum
- 12
- Digital root
- 3
Representations
- Decimal
- 48
- Scientific notation
- 4.800 × 10^1
Roman numerals
X L V I I I
XLVIII uses the subtractive pair XL: ten before fifty — fifty minus ten.
Binary
1 1 0 0 0 0
1 × 32 + 1 × 16 + 0 × 8 + 0 × 4 + 0 × 2 + 0 × 1 = 48
Octal
6 0
6 × 8 + 0 × 1 = 48
Hexadecimal
3 0
3 × 16 + 0 × 1 = 48
Read as powers of two: 32 + 16 = 48.
In historical numeral systems
Egyptian
4 hobbles, 8 strokes
4 × 10 + 8 × 1 = 48. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
4 corner wedges + 8 vertical wedges
48 fits in a single sexagesimal place: 4 corner wedges + 8 vertical wedges.
Greek (Ionic)
mu, then eta, marked as a numeral
mu-eta + keraia
mu + eta written in descending order and added — the letters carry their values wherever they stand, so this is addition, not place value.
Hebrew numerals
mem, then het
mem-het
mem (40) + het (8) = 48, written in descending order.
Chinese numerals
sì shí bā
sì shí bā
四 before 十 multiplies it: 4 tens. 八 after it adds 8. The written form mirrors the arithmetic — "sì shí bā". The financial (anti-fraud) form is 肆拾捌.
Maya
2 dots (upper, twenties place) over 1 bar + 3 dots (lower, units place)
2 × 20 + 8 = 48. Places stack vertically with the smallest at the bottom, so the upper group is worth twenty times the lower.
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
- Highly composite number
- Harshad (Niven) number
Related numbers & connections
24 is a factor of 48 (24 × 2 = 48).
View 24 →Forty-eight states are contiguous, the count before Alaska and Hawaii were admitted in 1959.
Poland's ISO numeric code and calling code, both stable across border and constitutional changes.
View 616 →Mathematically related
Numbers Around Us
- appears inContiguous United States
why?
Strength 0.50, confidence "high".
Technology & computing
48,000 samples per second is the standard audio sample rate for film, television and professional recording, where CD audio uses 44,100. The split is historical rather than acoustic: 44.1 kHz was chosen to fit audio onto video tape, while 48 kHz divides cleanly by common video frame rates, which is why the two have never merged.
DocumentedTechnology & computing
Geography
The 48 contiguous United States are the US states located on the North American mainland, excluding Alaska and Hawaii.
DocumentedGeographyGeography: United States
Mathematics
48 is a highly composite number: it has ten divisors, more than any smaller number manages. That divisibility is why it recurs in packaging, timekeeping and measurement wherever quantities need splitting several ways.
DocumentedMathematics
Science
48 is the atomic number of cadmium. Once common in rechargeable NiCd batteries and bright yellow and red pigments, its toxicity has since driven it out of most consumer uses.
DocumentedScience
Common questions
Why are they called the lower 48?
They are the states on the North American mainland — everything except Alaska and Hawaii, which joined in 1959. 'Lower 48' is the usual American term, 'contiguous United States' the formal one, and the two mean the same set.
Is 48 a prime number?
No, 48 is not prime.
What are the factors of 48?
The factors of 48 are 1, 2, 3, 4, 6, 8, 12, 16, 24, 48.
What is 48 in Roman numerals?
48 in Roman numerals is XLVIII. XL is subtractive: ten before fifty — fifty minus ten. Written additively it would be XXXXVIII, 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: 4 reviewer-confirmed records, sourced and reviewed before publication.
Last reviewed: 15 July 2026