+821 is a [natural number](/wiki/Natural_number) and a prime number, appearing between 820 and 822. As a [prime number](/wiki/Prime_number), its only positive divisors are 1 and itself, representing an indivisible quantity in the sequence of integers.
+## See also
+- [Number](/wiki/Number)
+- [Prime](/wiki/Prime)
+- [Integer](/wiki/Integer)