1669609 has 4 divisors (see below), whose sum is σ = 1680016. Its totient is φ = 1659204.

The previous prime is 1669597. The next prime is 1669627. The reversal of 1669609 is 9069661.

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 1669609 - 2⁹ = 1669097 is a prime.

It is a Duffinian number.

1669609 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1669649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4959 + ... + 5284.

It is an arithmetic number, because the mean of its divisors is an integer number (420004).

2^1669609 is an apocalyptic number.

It is an amenable number.

1669609 is a deficient number, since it is larger than the sum of its proper divisors (10407).

1669609 is a wasteful number, since it uses less digits than its factorization.

1669609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10406.

The product of its (nonzero) digits is 17496, while the sum is 37.

The square root of 1669609 is about 1292.1335070340. The cubic root of 1669609 is about 118.6328395705.

It can be divided in two parts, 1669 and 609, that added together give a triangular number (2278 = T₆₇).

The spelling of 1669609 in words is "one million, six hundred sixty-nine thousand, six hundred nine".