6643

6643 is a natural number that follows 6642 and precedes 6644. In mathematics, it is studied for its factorization and arithmetic properties as a specific integer.

Its prime factorization is 7 × 13 × 73, so 6643 is a sphenic number (the product of three distinct primes). Accordingly, it has eight positive divisors: 1, 7, 13, 73, 91 (7×13), 511 (7×73), 949 (13×73), and 6643 itself.

The Euler totient of 6643 is φ(6643) = 5184, since for a product of three distinct primes p, q, r, φ(n) = (p−1)(q−1)(r−1). The sum of all divisors is σ(6643) = 8288, giving a sum of proper divisors equal to 1645. Consequently, 6643 is a deficient number, as the sum of its proper divisors is less than the number itself. It is also odd.

In common numeral systems, 6643 is represented as 0x19F3 in hexadecimal and 1100111110011 in binary.

Overall, 6643 is notable mainly for being a relatively small sphenic number with a straightforward prime factorization and the usual accompanying divisor-related properties.