820844 has 6 divisors (see below), whose sum is σ = 1436484. Its totient is φ = 410420.

The previous prime is 820837. The next prime is 820873. The reversal of 820844 is 448028.

It is an Ulam number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102602 + ... + 102609.

It is an arithmetic number, because the mean of its divisors is an integer number (239414).

2⁸²⁰⁸⁴⁴ is an apocalyptic number.

It is an amenable number.

820844 is a deficient number, since it is larger than the sum of its proper divisors (615640).

820844 is a wasteful number, since it uses less digits than its factorization.

820844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205215 (or 205213 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 26.

The square root of 820844 is about 906.0044150003. The cubic root of 820844 is about 93.6311180533.

Subtracting from 820844 its reverse (448028), we obtain a triangular number (372816 = T₈₆₃).

The spelling of 820844 in words is "eight hundred twenty thousand, eight hundred forty-four".