821828 has 24 divisors (see below), whose sum is σ = 1680000. Its totient is φ = 351624.

The previous prime is 821827. The next prime is 821833. The reversal of 821828 is 828128.

It is a plaindrome in base 15.

It is a nialpdrome in base 7.

It is a self number, because there is not a number n which added to its sum of digits gives 821828.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 821828.

It is not an unprimeable number, because it can be changed into a prime (821827) 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, 1073 + ... + 1671.

It is an arithmetic number, because the mean of its divisors is an integer number (70000).

2⁸²¹⁸²⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 821828, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (840000).

821828 is an abundant number, since it is smaller than the sum of its proper divisors (858172).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

821828 is a wasteful number, since it uses less digits than its factorization.

821828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 624 (or 608 counting only the distinct ones).

The product of its digits is 2048, while the sum is 29.

The square root of 821828 is about 906.5472960635. The cubic root of 821828 is about 93.6685170513.

The spelling of 821828 in words is "eight hundred twenty-one thousand, eight hundred twenty-eight".