816589 has 2 divisors, whose sum is σ = 816590. Its totient is φ = 816588.

The previous prime is 816587. The next prime is 816593. The reversal of 816589 is 985618.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 514089 + 302500 = 717^2 + 550^2 .

It is a cyclic number.

It is not a de Polignac number, because 816589 - 2¹ = 816587 is a prime.

Together with 816587, it forms a pair of twin primes.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (816581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 408294 + 408295.

It is an arithmetic number, because the mean of its divisors is an integer number (408295).

2⁸¹⁶⁵⁸⁹ is an apocalyptic number.

It is an amenable number.

816589 is a deficient number, since it is larger than the sum of its proper divisors (1).

816589 is an equidigital number, since it uses as much as digits as its factorization.

816589 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17280, while the sum is 37.

The square root of 816589 is about 903.6531414210. The cubic root of 816589 is about 93.4690528330.

It can be divided in two parts, 81 and 6589, that added together give a triangular number (6670 = T₁₁₅).

The spelling of 816589 in words is "eight hundred sixteen thousand, five hundred eighty-nine".