669605 has 8 divisors (see below), whose sum is σ = 809592. Its totient is φ = 531648.

The previous prime is 669577. The next prime is 669607. The reversal of 669605 is 506966.

It can be written as a sum of positive squares in 4 ways, for example, as 2116 + 667489 = 46^2 + 817^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 669605 - 2¹⁰ = 668581 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 669605.

It is not an unprimeable number, because it can be changed into a prime (669607) 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 7 ways as a sum of consecutive naturals, for example, 359 + ... + 1211.

It is an arithmetic number, because the mean of its divisors is an integer number (101199).

2⁶⁶⁹⁶⁰⁵ is an apocalyptic number.

It is an amenable number.

669605 is a deficient number, since it is larger than the sum of its proper divisors (139987).

669605 is a wasteful number, since it uses less digits than its factorization.

669605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1015.

The product of its (nonzero) digits is 9720, while the sum is 32.

The square root of 669605 is about 818.2939569617. The cubic root of 669605 is about 87.4862019059.

The spelling of 669605 in words is "six hundred sixty-nine thousand, six hundred five".