820785 has 16 divisors (see below), whose sum is σ = 1501056. Its totient is φ = 375168.

The previous prime is 820763. The next prime is 820789. The reversal of 820785 is 587028.

It is not a de Polignac number, because 820785 - 2⁵ = 820753 is a prime.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (820789) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3804 + ... + 4013.

It is an arithmetic number, because the mean of its divisors is an integer number (93816).

2⁸²⁰⁷⁸⁵ is an apocalyptic number.

It is an amenable number.

820785 is a deficient number, since it is larger than the sum of its proper divisors (680271).

820785 is a wasteful number, since it uses less digits than its factorization.

820785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7832.

The product of its (nonzero) digits is 4480, while the sum is 30.

The square root of 820785 is about 905.9718538674. The cubic root of 820785 is about 93.6288746842.

The spelling of 820785 in words is "eight hundred twenty thousand, seven hundred eighty-five".