28163609 has 4 divisors (see below), whose sum is σ = 28176000. Its totient is φ = 28151220.

The previous prime is 28163587. The next prime is 28163621. The reversal of 28163609 is 90636182.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 28163609 - 2⁸ = 28163353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28163689) 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, 1697 + ... + 7694.

It is an arithmetic number, because the mean of its divisors is an integer number (7044000).

Almost surely, 2^28163609 is an apocalyptic number.

It is an amenable number.

28163609 is a deficient number, since it is larger than the sum of its proper divisors (12391).

28163609 is an equidigital number, since it uses as much as digits as its factorization.

28163609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12390.

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 28163609 is about 5306.9397019375. The cubic root of 28163609 is about 304.2491933279.

The spelling of 28163609 in words is "twenty-eight million, one hundred sixty-three thousand, six hundred nine".