28030809 has 4 divisors (see below), whose sum is σ = 37374416. Its totient is φ = 18687204.

The previous prime is 28030801. The next prime is 28030811. The reversal of 28030809 is 90803082.

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 not a de Polignac number, because 28030809 - 2³ = 28030801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28030801) 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, 4671799 + ... + 4671804.

It is an arithmetic number, because the mean of its divisors is an integer number (9343604).

Almost surely, 2^28030809 is an apocalyptic number.

It is an amenable number.

28030809 is a deficient number, since it is larger than the sum of its proper divisors (9343607).

28030809 is an equidigital number, since it uses as much as digits as its factorization.

28030809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9343606.

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 28030809 is about 5294.4129986241. The cubic root of 28030809 is about 303.7702304939.

The spelling of 28030809 in words is "twenty-eight million, thirty thousand, eight hundred nine".