669409 has 12 divisors (see below), whose sum is σ = 770796. Its totient is φ = 579072.

The previous prime is 669401. The next prime is 669413. The reversal of 669409 is 904966.

669409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 6 ways, for example, as 102400 + 567009 = 320^2 + 753^2 .

It is not a de Polignac number, because 669409 - 2³ = 669401 is a prime.

It is not an unprimeable number, because it can be changed into a prime (669401) 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, 2757 + ... + 2989.

It is an arithmetic number, because the mean of its divisors is an integer number (64233).

2⁶⁶⁹⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

669409 is a deficient number, since it is larger than the sum of its proper divisors (101387).

669409 is a wasteful number, since it uses less digits than its factorization.

669409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276 (or 263 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 34.

The square root of 669409 is about 818.1741868331. The cubic root of 669409 is about 87.4776650476.

The spelling of 669409 in words is "six hundred sixty-nine thousand, four hundred nine".