698809 has 6 divisors (see below), whose sum is σ = 731066. Its totient is φ = 667920.

The previous prime is 698779. The next prime is 698821. The reversal of 698809 is 908896.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 685584 + 13225 = 828^2 + 115^2 .

It is not a de Polignac number, because 698809 - 2⁹ = 698297 is a prime.

It is a Duffinian number.

698809 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (698849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 132 + ... + 1189.

2⁶⁹⁸⁸⁰⁹ is an apocalyptic number.

698809 is the 529-th heptagonal number.

It is an amenable number.

698809 is a deficient number, since it is larger than the sum of its proper divisors (32257).

698809 is a wasteful number, since it uses less digits than its factorization.

698809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1367 (or 1344 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 698809 is about 835.9479648878. The cubic root of 698809 is about 88.7400147465.

The spelling of 698809 in words is "six hundred ninety-eight thousand, eight hundred nine".