820656 has 60 divisors (see below), whose sum is σ = 2369640. Its totient is φ = 264960.

The previous prime is 820649. The next prime is 820657. The reversal of 820656 is 656028.

820656 is a `hidden beast` number, since 8 + 2 + 0 + 656 = 666.

It is not an unprimeable number, because it can be changed into a prime (820657) 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, 5835 + ... + 5973.

It is an arithmetic number, because the mean of its divisors is an integer number (39494).

2⁸²⁰⁶⁵⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 820656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1184820).

820656 is an abundant number, since it is smaller than the sum of its proper divisors (1548984).

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

820656 is a wasteful number, since it uses less digits than its factorization.

820656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194 (or 185 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 820656 is about 905.9006568051. The cubic root of 820656 is about 93.6239693161.

The spelling of 820656 in words is "eight hundred twenty thousand, six hundred fifty-six".