28105729 has 2 divisors, whose sum is σ = 28105730. Its totient is φ = 28105728.

The previous prime is 28105723. The next prime is 28105733. The reversal of 28105729 is 92750182.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18662400 + 9443329 = 4320^2 + 3073^2 .

It is a cyclic number.

It is not a de Polignac number, because 28105729 - 2⁵ = 28105697 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28105694 and 28105703.

It is not a weakly prime, because it can be changed into another prime (28105723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14052864 + 14052865.

It is an arithmetic number, because the mean of its divisors is an integer number (14052865).

Almost surely, 2^28105729 is an apocalyptic number.

It is an amenable number.

28105729 is a deficient number, since it is larger than the sum of its proper divisors (1).

28105729 is an equidigital number, since it uses as much as digits as its factorization.

28105729 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 28105729 is about 5301.4836602596. The cubic root of 28105729 is about 304.0406260629.

The spelling of 28105729 in words is "twenty-eight million, one hundred five thousand, seven hundred twenty-nine".