821028 has 48 divisors (see below), whose sum is σ = 2179520. Its totient is φ = 238464.

The previous prime is 821027. The next prime is 821039. The reversal of 821028 is 820128.

It is a junction number, because it is equal to n+sod(n) for n = 820995 and 821013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821027) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2826 + ... + 3102.

2⁸²¹⁰²⁸ 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 821028, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1089760).

821028 is an abundant number, since it is smaller than the sum of its proper divisors (1358492).

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

821028 is a wasteful number, since it uses less digits than its factorization.

821028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 316 (or 314 counting only the distinct ones).

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

The square root of 821028 is about 906.1059540694. The cubic root of 821028 is about 93.6381136329.

Subtracting from 821028 its reverse (820128), we obtain a square (900 = 30²).

The spelling of 821028 in words is "eight hundred twenty-one thousand, twenty-eight".