82021 has 2 divisors, whose sum is σ = 82022.
Its totient is φ = 82020.
The previous prime is 82013. The next prime is 82031. The reversal of 82021 is 12028.
Adding to 82021 its reverse (12028), we get a palindrome (94049).
It can be divided in two parts, 820 and 21, that added together give a square (841 = 292).
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 81796 + 225 = 286^2 + 15^2
It is a cyclic number.
It is not a de Polignac number, because 82021 - 23 = 82013 is a prime.
It is a junction number, because it is equal to n+sod(n) for n = 81992 and 82010.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (82031) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41010 + 41011.
It is an arithmetic number, because the mean of its divisors is an integer number (41011).
282021 is an apocalyptic number.
It is an amenable number.
82021 is a deficient number, since it is larger than the sum of its proper divisors (1).
82021 is an equidigital number, since it uses as much as digits as its factorization.
82021 is an evil number, because the sum of its binary digits is even.
The product of its (nonzero) digits is 32, while the sum is 13.
The square root of 82021 is about 286.3930865087.
The cubic root of 82021 is about 43.4485232448.
The spelling of 82021 in words is "eighty-two thousand, twenty-one".