820825 has 6 divisors (see below), whose sum is σ = 1017854. Its totient is φ = 656640.

The previous prime is 820793. The next prime is 820837. The reversal of 820825 is 528028.

It can be written as a sum of positive squares in 3 ways, for example, as 82944 + 737881 = 288^2 + 859^2 .

It is not a de Polignac number, because 820825 - 2⁵ = 820793 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25), and also a Moran number because the ratio is a prime number: 32833 = 820825 / (8 + 2 + 0 + 8 + 2 + 5).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 820825.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 16392 + ... + 16441.

2⁸²⁰⁸²⁵ is an apocalyptic number.

It is an amenable number.

820825 is a deficient number, since it is larger than the sum of its proper divisors (197029).

820825 is a wasteful number, since it uses less digits than its factorization.

820825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32843 (or 32838 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 25.

The square root of 820825 is about 905.9939293395. The cubic root of 820825 is about 93.6303956242.

The spelling of 820825 in words is "eight hundred twenty thousand, eight hundred twenty-five".