28323809 has 2 divisors, whose sum is σ = 28323810. Its totient is φ = 28323808.

The previous prime is 28323803. The next prime is 28323811. The reversal of 28323809 is 90832382.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18464209 + 9859600 = 4297^2 + 3140^2 .

It is a cyclic number.

It is not a de Polignac number, because 28323809 - 2²⁰ = 27275233 is a prime.

Together with 28323811, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28323803) 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 as a sum of consecutive naturals, namely, 14161904 + 14161905.

It is an arithmetic number, because the mean of its divisors is an integer number (14161905).

Almost surely, 2^28323809 is an apocalyptic number.

It is an amenable number.

28323809 is a deficient number, since it is larger than the sum of its proper divisors (1).

28323809 is an equidigital number, since it uses as much as digits as its factorization.

28323809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 35.

The square root of 28323809 is about 5322.0117436924. The cubic root of 28323809 is about 304.8249788649.

The spelling of 28323809 in words is "twenty-eight million, three hundred twenty-three thousand, eight hundred nine".