820806 has 16 divisors (see below), whose sum is σ = 1876224. Its totient is φ = 234504.

The previous prime is 820793. The next prime is 820837. The reversal of 820806 is 608028.

820806 = T₂₂₈ + T₂₂₉ + ... + T₂₅₅.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

820806 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9730 + ... + 9813.

It is an arithmetic number, because the mean of its divisors is an integer number (117264).

2⁸²⁰⁸⁰⁶ is an apocalyptic number.

820806 is an abundant number, since it is smaller than the sum of its proper divisors (1055418).

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

820806 is a wasteful number, since it uses less digits than its factorization.

820806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19555.

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 820806 is about 905.9834435573. The cubic root of 820806 is about 93.6296731838.

The spelling of 820806 in words is "eight hundred twenty thousand, eight hundred six".