818689 has 2 divisors, whose sum is σ = 818690. Its totient is φ = 818688.

The previous prime is 818687. The next prime is 818707. The reversal of 818689 is 986818.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 588289 + 230400 = 767^2 + 480^2 .

It is a cyclic number.

It is not a de Polignac number, because 818689 - 2¹ = 818687 is a prime.

Together with 818687, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (818683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 409344 + 409345.

It is an arithmetic number, because the mean of its divisors is an integer number (409345).

2⁸¹⁸⁶⁸⁹ is an apocalyptic number.

It is an amenable number.

818689 is a deficient number, since it is larger than the sum of its proper divisors (1).

818689 is an equidigital number, since it uses as much as digits as its factorization.

818689 is an odious number, because the sum of its binary digits is odd.

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

The square root of 818689 is about 904.8143455980. The cubic root of 818689 is about 93.5491081977.

The spelling of 818689 in words is "eight hundred eighteen thousand, six hundred eighty-nine".