820344 has 64 divisors (see below), whose sum is σ = 2476800. Its totient is φ = 221184.

The previous prime is 820343. The next prime is 820349. The reversal of 820344 is 443028.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 820344.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820343) 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, 3064 + ... + 3320.

It is an arithmetic number, because the mean of its divisors is an integer number (38700).

2⁸²⁰³⁴⁴ is an apocalyptic number.

820344 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 820344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1238400).

820344 is an abundant number, since it is smaller than the sum of its proper divisors (1656456).

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

820344 is a wasteful number, since it uses less digits than its factorization.

820344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292 (or 288 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

The square root of 820344 is about 905.7284361220. The cubic root of 820344 is about 93.6121030445.

The spelling of 820344 in words is "eight hundred twenty thousand, three hundred forty-four".