820556 has 24 divisors (see below), whose sum is σ = 1660176. Its totient is φ = 350720.

The previous prime is 820541. The next prime is 820559. The reversal of 820556 is 655028.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 820556.

It is not an unprimeable number, because it can be changed into a prime (820559) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 200 + ... + 1296.

It is an arithmetic number, because the mean of its divisors is an integer number (69174).

2⁸²⁰⁵⁵⁶ is an apocalyptic number.

It is an amenable number.

820556 is an abundant number, since it is smaller than the sum of its proper divisors (839620).

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

820556 is a wasteful number, since it uses less digits than its factorization.

820556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1129 (or 1127 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 820556 is about 905.8454614337. The cubic root of 820556 is about 93.6201663515.

The spelling of 820556 in words is "eight hundred twenty thousand, five hundred fifty-six".