669445 has 16 divisors (see below), whose sum is σ = 949248. Its totient is φ = 443520.

The previous prime is 669437. The next prime is 669451. The reversal of 669445 is 544966.

It is not a de Polignac number, because 669445 - 2³ = 669437 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 669445.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 777 + ... + 1393.

It is an arithmetic number, because the mean of its divisors is an integer number (59328).

2⁶⁶⁹⁴⁴⁵ is an apocalyptic number.

It is an amenable number.

669445 is a deficient number, since it is larger than the sum of its proper divisors (279803).

669445 is a wasteful number, since it uses less digits than its factorization.

669445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 660.

The product of its digits is 25920, while the sum is 34.

The square root of 669445 is about 818.1961867425. The cubic root of 669445 is about 87.4792331669.

The spelling of 669445 in words is "six hundred sixty-nine thousand, four hundred forty-five".