Number reference
1729 explained.
1729: one thousand seven hundred twenty-nine, composite; factors, prime factorization, roots, binary, hexadecimal, and digit properties.
Identity and representations
- Written form
- one thousand seven hundred twenty-nine
- Classification
- composite
- Factors
- 1, 7, 13, 19, 91, 133, 247, 1729
- Prime factorization
- 7 × 13 × 19
- Square root
- 41.581246
- Cube root
- 12.002314
- Binary
- 11011000001
- Octal
- 3301
- Hexadecimal
- 6C1
- Roman numeral
- MDCCXXIX
- Digit sum
- 19
- Digital root
- 1
What makes 1729 notable
- Factor structure. 1729 breaks down into 3 distinct primes (7, 13, 19) and has 8 divisors in total, so it can be split into equal whole-number groups 6 ways beyond 1 and itself.
1729 in everyday use
One thousand seven hundred twenty-nine is the Hardy–Ramanujan number, the smallest number expressible as a sum of two positive cubes in two different ways: 1³ + 12³ and 9³ + 10³. It is named for Ramanujan's reply when Hardy called the number of his taxicab "rather dull".
Nearby numbers
How to read this page
The factor list shows every way 1729 splits into equal whole-number groups — 8 divisors in total. The prime factorisation is the compact form of that same information, and the base conversions restate 1729 for contexts that do not use decimal.
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