690909 has 4 divisors (see below), whose sum is σ = 921216. Its totient is φ = 460604.

The previous prime is 690889. The next prime is 690919. The reversal of 690909 is 909096.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 690909 - 2⁹ = 690397 is a prime.

It is a D-number.

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

690909 is a modest number, since divided by 909 gives 69 as remainder.

It is a Curzon number.

690909 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 690909.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (690919) 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 3 ways as a sum of consecutive naturals, for example, 115149 + ... + 115154.

It is an arithmetic number, because the mean of its divisors is an integer number (230304).

2⁶⁹⁰⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

690909 is a deficient number, since it is larger than the sum of its proper divisors (230307).

690909 is a wasteful number, since it uses less digits than its factorization.

690909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 230306.

The product of its (nonzero) digits is 4374, while the sum is 33.

The square root of 690909 is about 831.2093599088. The cubic root of 690909 is about 88.4043462029.

The spelling of 690909 in words is "six hundred ninety thousand, nine hundred nine".