820817 has 4 divisors (see below), whose sum is σ = 833136. Its totient is φ = 808500.

The previous prime is 820793. The next prime is 820837. The reversal of 820817 is 718028.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 820817 - 2⁶ = 820753 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is a zygodrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (820837) 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, 6059 + ... + 6192.

It is an arithmetic number, because the mean of its divisors is an integer number (208284).

2⁸²⁰⁸¹⁷ is an apocalyptic number.

It is an amenable number.

820817 is a deficient number, since it is larger than the sum of its proper divisors (12319).

820817 is a wasteful number, since it uses less digits than its factorization.

820817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12318.

The product of its (nonzero) digits is 896, while the sum is 26.

The square root of 820817 is about 905.9895142881. The cubic root of 820817 is about 93.6300914401.

The spelling of 820817 in words is "eight hundred twenty thousand, eight hundred seventeen".