8721

8721 is a natural number that lies between 8720 and 8722. In number theory it has the prime factorization 8721 = 3^3 × 17 × 19, making it a composite, odd integer. It has 16 positive divisors, computed from the exponents in the factorization as (3+1)(1+1)(1+1) = 16. The number is not a prime and it is not a perfect square.

In base representation, 8721 equals 10001000010001 in binary, and 0x2211 in hexadecimal. The hexadecimal value 0x2211 corresponds to the decimal code point 8721 in Unicode, where U+2211 is the N-ary summation symbol ∑, used in mathematics to denote summation over multiple indices.

Number-theoretic properties related to 8721 include its relation to sums of two squares. Because the prime factors 3 and 19 are each congruent to 3 modulo 4 and occur to odd powers, 8721 cannot be expressed as a sum of two squares.

Beyond its mathematical aspects, 8721 may appear as a numeric identifier in various catalogs, datasets, or model numbers, but there is no widely recognized meaning specific to the number itself.