689805 has 12 divisors (see below), whose sum is σ = 1195740. Its totient is φ = 367872.

The previous prime is 689803. The next prime is 689807. The reversal of 689805 is 508986.

It is an interprime number because it is at equal distance from previous prime (689803) and next prime (689807).

It can be written as a sum of positive squares in 2 ways, for example, as 145161 + 544644 = 381^2 + 738^2 .

It is not a de Polignac number, because 689805 - 2¹ = 689803 is a prime.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 689805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (689803) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7620 + ... + 7709.

It is an arithmetic number, because the mean of its divisors is an integer number (99645).

2⁶⁸⁹⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

689805 is a deficient number, since it is larger than the sum of its proper divisors (505935).

689805 is a wasteful number, since it uses less digits than its factorization.

689805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15340 (or 15337 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 689805 is about 830.5450017910. The cubic root of 689805 is about 88.3572341479.

The spelling of 689805 in words is "six hundred eighty-nine thousand, eight hundred five".