820565028 has 36 divisors (see below), whose sum is σ = 2075083920. Its totient is φ = 273405936.

The previous prime is 820565017. The next prime is 820565033.

820565028 is nontrivially palindromic in base 10.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 820564983 and 820565001.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 146251 + ... + 151757.

It is an arithmetic number, because the mean of its divisors is an integer number (57641220).

Almost surely, 2^820565028 is an apocalyptic number.

It is an amenable number.

820565028 is an abundant number, since it is smaller than the sum of its proper divisors (1254518892).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

820565028 is a wasteful number, since it uses less digits than its factorization.

820565028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9656 (or 9651 counting only the distinct ones).

The product of its (nonzero) digits is 38400, while the sum is 36.

The square root of 820565028 is about 28645.5062444356. The cubic root of 820565028 is about 936.2050969580.

The spelling of 820565028 in words is "eight hundred twenty million, five hundred sixty-five thousand, twenty-eight".