821304 has 96 divisors (see below), whose sum is σ = 2611440. Its totient is φ = 230400.

The previous prime is 821297. The next prime is 821311. The reversal of 821304 is 403128.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (821297) and next prime (821311).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 13434 + ... + 13494.

2⁸²¹³⁰⁴ 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 821304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1305720).

821304 is an abundant number, since it is smaller than the sum of its proper divisors (1790136).

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

821304 is a wasteful number, since it uses less digits than its factorization.

821304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101 (or 94 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 821304 is about 906.2582413418. The cubic root of 821304 is about 93.6486050429.

It can be divided in two parts, 8 and 21304, that added together give a palindrome (21312).

The spelling of 821304 in words is "eight hundred twenty-one thousand, three hundred four".