820445 has 4 divisors (see below), whose sum is σ = 984540. Its totient is φ = 656352.

The previous prime is 820441. The next prime is 820459. The reversal of 820445 is 544028.

820445 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 643204 + 177241 = 802^2 + 421^2 .

It is a cyclic number.

It is not a de Polignac number, because 820445 - 2² = 820441 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 820445.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 820445.

It is not an unprimeable number, because it can be changed into a prime (820441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82040 + ... + 82049.

It is an arithmetic number, because the mean of its divisors is an integer number (246135).

2⁸²⁰⁴⁴⁵ is an apocalyptic number.

It is an amenable number.

820445 is a deficient number, since it is larger than the sum of its proper divisors (164095).

820445 is a wasteful number, since it uses less digits than its factorization.

820445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164094.

The product of its (nonzero) digits is 1280, while the sum is 23.

The square root of 820445 is about 905.7841906326. The cubic root of 820445 is about 93.6159446989.

The spelling of 820445 in words is "eight hundred twenty thousand, four hundred forty-five".