821104 has 40 divisors (see below), whose sum is σ = 1743440. Its totient is φ = 373248.

The previous prime is 821101. The next prime is 821113. The reversal of 821104 is 401128.

821104 = T₁₁₂ + T₁₁₃ + ... + T₁₈₄.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a nialpdrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11212 + ... + 11284.

It is an arithmetic number, because the mean of its divisors is an integer number (43586).

2⁸²¹¹⁰⁴ 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 821104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (871720).

821104 is an abundant number, since it is smaller than the sum of its proper divisors (922336).

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

821104 is a wasteful number, since it uses less digits than its factorization.

821104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137 (or 131 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 821104 is about 906.1478907993. The cubic root of 821104 is about 93.6410028065.

It can be divided in two parts, 8 and 21104, that added together give a palindrome (21112).

The spelling of 821104 in words is "eight hundred twenty-one thousand, one hundred four".