820885 has 16 divisors (see below), whose sum is σ = 1081584. Its totient is φ = 594432.

The previous prime is 820873. The next prime is 820891. The reversal of 820885 is 588028.

It can be written as a sum of positive squares in 8 ways, for example, as 49 + 820836 = 7^2 + 906^2 .

It is a cyclic number.

It is not a de Polignac number, because 820885 - 2¹¹ = 818837 is a prime.

It is a Duffinian number.

It is a plaindrome in base 15.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4659 + ... + 4831.

It is an arithmetic number, because the mean of its divisors is an integer number (67599).

2⁸²⁰⁸⁸⁵ is an apocalyptic number.

It is an amenable number.

820885 is a deficient number, since it is larger than the sum of its proper divisors (260699).

820885 is a wasteful number, since it uses less digits than its factorization.

820885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 264.

The product of its (nonzero) digits is 5120, while the sum is 31.

The square root of 820885 is about 906.0270415390. The cubic root of 820885 is about 93.6326769415.

The spelling of 820885 in words is "eight hundred twenty thousand, eight hundred eighty-five".