Number reference
6 explained.
6: six, composite, perfect number; factors, prime factorization, roots, binary, hexadecimal, and digit properties.
Identity and representations
- Written form
- six
- Classification
- composite
- Factors
- 1, 2, 3, 6
- Prime factorization
- 2 × 3
- Square root
- 2.44949
- Cube root
- 1.817121
- Binary
- 110
- Octal
- 6
- Hexadecimal
- 6
- Roman numeral
- VI
- Digit sum
- 6
- Digital root
- 6
What makes 6 notable
- Perfect number. 6 is a perfect number — its proper divisors (1 + 2 + 3) sum to exactly 6. Only three perfect numbers exist below one thousand.
- Factorial. 6 = 3! — the product of every whole number from 1 to 3. It counts the ways 3 distinct items can be put in order.
- Triangular number. 6 is the 3rd triangular number: it is the sum 1 + 2 + … + 3, the count of items in a triangle with 3 rows.
- Highly composite. 6 has 4 divisors — more than any smaller positive number. That is why numbers like this get chosen for units of time, angle, and packaging.
6 in everyday use
Six is the atomic number of carbon, the element every living cell is built around. Honeycomb cells and snowflakes are six-sided, a standard die has six faces, a guitar six strings, and a volleyball team six players on court. Half a dozen is a natural packaging count because it splits into halves and thirds. Insects have six legs, which is what separates them from spiders. The six-day week of creation followed by a day of rest is shared by Jewish and Christian scripture.
Six is the smallest perfect number: its proper divisors 1, 2, and 3 add up to exactly 6. It is also their product, making it the only number that is both the sum and the product of the same three consecutive integers. It equals 3 factorial, the number of ways to arrange three objects, and it is the third triangular number. Six is the smallest number that has two different prime factors, 2 and 3.
Nearby numbers
How to read this page
The factor list shows every way 6 splits into equal whole-number groups — 4 divisors in total. The prime factorisation is the compact form of that same information, and the base conversions restate 6 for contexts that do not use decimal.
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