821328 has 40 divisors (see below), whose sum is σ = 2160576. Its totient is φ = 268800.

The previous prime is 821311. The next prime is 821329. The reversal of 821328 is 823128.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a nude number because it is divisible by every one of its digits.

It is a nialpdrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 821298 and 821307.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821329) by changing a digit.

821328 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3288 + ... + 3528.

2⁸²¹³²⁸ 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 821328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1080288).

821328 is an abundant number, since it is smaller than the sum of its proper divisors (1339248).

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

821328 is a wasteful number, since it uses less digits than its factorization.

821328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323 (or 317 counting only the distinct ones).

The product of its digits is 768, while the sum is 24.

The square root of 821328 is about 906.2714825040. The cubic root of 821328 is about 93.6495172283.

The spelling of 821328 in words is "eight hundred twenty-one thousand, three hundred twenty-eight".