28669609 has 4 divisors (see below), whose sum is σ = 28705104. Its totient is φ = 28634116.

The previous prime is 28669591. The next prime is 28669639. The reversal of 28669609 is 90696682.

It is a happy number.

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 28669609 - 2⁹ = 28669097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28669639) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16507 + ... + 18160.

It is an arithmetic number, because the mean of its divisors is an integer number (7176276).

Almost surely, 2^28669609 is an apocalyptic number.

It is an amenable number.

28669609 is a deficient number, since it is larger than the sum of its proper divisors (35495).

28669609 is an equidigital number, since it uses as much as digits as its factorization.

28669609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35494.

The product of its (nonzero) digits is 279936, while the sum is 46.

The square root of 28669609 is about 5354.4009001942. The cubic root of 28669609 is about 306.0604811602.

The spelling of 28669609 in words is "twenty-eight million, six hundred sixty-nine thousand, six hundred nine".