28510813 has 2 divisors, whose sum is σ = 28510814. Its totient is φ = 28510812.

The previous prime is 28510789. The next prime is 28510861. The reversal of 28510813 is 31801582.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14953689 + 13557124 = 3867^2 + 3682^2 .

It is a cyclic number.

It is not a de Polignac number, because 28510813 - 2⁹ = 28510301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28510613) 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, 14255406 + 14255407.

It is an arithmetic number, because the mean of its divisors is an integer number (14255407).

Almost surely, 2^28510813 is an apocalyptic number.

It is an amenable number.

28510813 is a deficient number, since it is larger than the sum of its proper divisors (1).

28510813 is an equidigital number, since it uses as much as digits as its factorization.

28510813 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 28510813 is about 5339.5517602136. The cubic root of 28510813 is about 305.4943626562.

The spelling of 28510813 in words is "twenty-eight million, five hundred ten thousand, eight hundred thirteen".