820917 has 12 divisors (see below), whose sum is σ = 1208844. Its totient is φ = 536640.

The previous prime is 820909. The next prime is 820921. The reversal of 820917 is 719028.

820917 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 599076 + 221841 = 774^2 + 471^2 .

It is not a de Polignac number, because 820917 - 2³ = 820909 is a prime.

It is a plaindrome in base 15.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 820917.

It is not an unprimeable number, because it can be changed into a prime (820907) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 384 + ... + 1337.

It is an arithmetic number, because the mean of its divisors is an integer number (100737).

2⁸²⁰⁹¹⁷ is an apocalyptic number.

It is an amenable number.

820917 is a deficient number, since it is larger than the sum of its proper divisors (387927).

820917 is a wasteful number, since it uses less digits than its factorization.

820917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1780 (or 1777 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 820917 is about 906.0447008840. The cubic root of 820917 is about 93.6338935986.

The spelling of 820917 in words is "eight hundred twenty thousand, nine hundred seventeen".