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About the number 55,993
55,993 is an odd composite number with the prime factorization 7 × 19 × 421, giving it exactly eight divisors. In hexadecimal it is written DAB9 and in binary 1101101010111001. Its digit sum is 31 and its digital root is 4. Read aloud in pairs — “55 · 99 · 3” — it is easy to remember, which is exactly why short numeric names are prized online.
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Primality and factorization use trial division optimized for odd divisors; divisor lists are generated for numbers up to one trillion. Triangular, square and Fibonacci checks use closed-form tests (for example, n is Fibonacci if 5n² ± 4 is a perfect square). Everything is computed locally in your browser.
Frequently asked questions
What is a perfect number?
A number equal to the sum of its proper divisors, like 6 (1 + 2 + 3) and 8128.
Why is 1729 famous?
It is the Hardy–Ramanujan number: the smallest number expressible as the sum of two cubes in two different ways (1³ + 12³ and 9³ + 10³).
What is a Harshad number?
A number divisible by the sum of its digits, such as 18 (1 + 8 = 9, and 18 ÷ 9 = 2).