820889 has 4 divisors (see below), whose sum is σ = 831360. Its totient is φ = 810420.

The previous prime is 820873. The next prime is 820891. The reversal of 820889 is 988028.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 820889 - 2⁴ = 820873 is a prime.

It is a Duffinian number.

It is a plaindrome in base 15.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 820889.

It is not an unprimeable number, because it can be changed into a prime (820489) 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, 5117 + ... + 5274.

It is an arithmetic number, because the mean of its divisors is an integer number (207840).

2⁸²⁰⁸⁸⁹ is an apocalyptic number.

It is an amenable number.

820889 is a deficient number, since it is larger than the sum of its proper divisors (10471).

820889 is a wasteful number, since it uses less digits than its factorization.

820889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10470.

The product of its (nonzero) digits is 9216, while the sum is 35.

The square root of 820889 is about 906.0292489760. The cubic root of 820889 is about 93.6328290254.

The spelling of 820889 in words is "eight hundred twenty thousand, eight hundred eighty-nine".