820843 has 4 divisors (see below), whose sum is σ = 822688. Its totient is φ = 819000.

The previous prime is 820837. The next prime is 820873. The reversal of 820843 is 348028.

820843 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 820843 - 2⁹ = 820331 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820873) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 205 + ... + 1297.

It is an arithmetic number, because the mean of its divisors is an integer number (205672).

2⁸²⁰⁸⁴³ is an apocalyptic number.

820843 is a deficient number, since it is larger than the sum of its proper divisors (1845).

820843 is a wasteful number, since it uses less digits than its factorization.

820843 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1844.

The product of its (nonzero) digits is 1536, while the sum is 25.

The square root of 820843 is about 906.0038631264. The cubic root of 820843 is about 93.6310800310.

The spelling of 820843 in words is "eight hundred twenty thousand, eight hundred forty-three".