28103809 has 2 divisors, whose sum is σ = 28103810. Its totient is φ = 28103808.

The previous prime is 28103783. The next prime is 28103827. The reversal of 28103809 is 90830182.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26010000 + 2093809 = 5100^2 + 1447^2 .

It is a cyclic number.

It is not a de Polignac number, because 28103809 - 2⁹ = 28103297 is a prime.

It is a super-3 number, since 3×28103809³ (a number of 23 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (28103879) 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, 14051904 + 14051905.

It is an arithmetic number, because the mean of its divisors is an integer number (14051905).

Almost surely, 2^28103809 is an apocalyptic number.

It is an amenable number.

28103809 is a deficient number, since it is larger than the sum of its proper divisors (1).

28103809 is an equidigital number, since it uses as much as digits as its factorization.

28103809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 28103809 is about 5301.3025757827. The cubic root of 28103809 is about 304.0337025481.

The spelling of 28103809 in words is "twenty-eight million, one hundred three thousand, eight hundred nine".