28625809 has 2 divisors, whose sum is σ = 28625810. Its totient is φ = 28625808.

The previous prime is 28625801. The next prime is 28625833. The reversal of 28625809 is 90852682.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22515025 + 6110784 = 4745^2 + 2472^2 .

It is a cyclic number.

It is not a de Polignac number, because 28625809 - 2³ = 28625801 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28625801) 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, 14312904 + 14312905.

It is an arithmetic number, because the mean of its divisors is an integer number (14312905).

Almost surely, 2^28625809 is an apocalyptic number.

It is an amenable number.

28625809 is a deficient number, since it is larger than the sum of its proper divisors (1).

28625809 is an equidigital number, since it uses as much as digits as its factorization.

28625809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 69120, while the sum is 40.

The square root of 28625809 is about 5350.3092433989. The cubic root of 28625809 is about 305.9045404031.

The spelling of 28625809 in words is "twenty-eight million, six hundred twenty-five thousand, eight hundred nine".