82821 has 8 divisors (see below), whose sum is σ = 116320. Its totient is φ = 52272.

The previous prime is 82813. The next prime is 82837. The reversal of 82821 is 12828.

82821 is nontrivially palindromic in base 2.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 82821 - 2³ = 82813 is a prime.

It is a Duffinian number.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 670 + ... + 783.

It is an arithmetic number, because the mean of its divisors is an integer number (14540).

2⁸²⁸²¹ is an apocalyptic number.

It is an amenable number.

82821 is a deficient number, since it is larger than the sum of its proper divisors (33499).

82821 is a wasteful number, since it uses less digits than its factorization.

82821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1475.

The product of its digits is 256, while the sum is 21.

The square root of 82821 is about 287.7863791078. The cubic root of 82821 is about 43.5893262877.

It can be divided in two parts, 82 and 821, that added together give a triangular number (903 = T₄₂).

The spelling of 82821 in words is "eighty-two thousand, eight hundred twenty-one".