820456 has 64 divisors (see below), whose sum is σ = 2016000. Its totient is φ = 310464.

The previous prime is 820441. The next prime is 820459. The reversal of 820456 is 654028.

It is an Ulam number.

It is a nialpdrome in base 7.

It is a zygodrome in base 7.

It is a self number, because there is not a number n which added to its sum of digits gives 820456.

It is not an unprimeable number, because it can be changed into a prime (820459) 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, 35661 + ... + 35683.

It is an arithmetic number, because the mean of its divisors is an integer number (31500).

2⁸²⁰⁴⁵⁶ 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 820456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1008000).

820456 is an abundant number, since it is smaller than the sum of its proper divisors (1195544).

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

820456 is a wasteful number, since it uses less digits than its factorization.

820456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63 (or 45 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 820456 is about 905.7902626988. The cubic root of 820456 is about 93.6163630778.

The spelling of 820456 in words is "eight hundred twenty thousand, four hundred fifty-six".