816889 has 4 divisors (see below), whose sum is σ = 832356. Its totient is φ = 801424.

The previous prime is 816887. The next prime is 816899. The reversal of 816889 is 988618.

It is a happy number.

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 652864 + 164025 = 808^2 + 405^2 .

It is a cyclic number.

It is not a de Polignac number, because 816889 - 2¹ = 816887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (816883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7654 + ... + 7759.

It is an arithmetic number, because the mean of its divisors is an integer number (208089).

2⁸¹⁶⁸⁸⁹ is an apocalyptic number.

It is an amenable number.

816889 is a deficient number, since it is larger than the sum of its proper divisors (15467).

816889 is a wasteful number, since it uses less digits than its factorization.

816889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15466.

The product of its digits is 27648, while the sum is 40.

The square root of 816889 is about 903.8191190720. The cubic root of 816889 is about 93.4804977102.

It can be divided in two parts, 81 and 6889, that multiplied together give a square (558009 = 747²).

The spelling of 816889 in words is "eight hundred sixteen thousand, eight hundred eighty-nine".