28717289 has 2 divisors, whose sum is σ = 28717290. Its totient is φ = 28717288.

The previous prime is 28717277. The next prime is 28717307. The reversal of 28717289 is 98271782.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19669225 + 9048064 = 4435^2 + 3008^2 .

It is a cyclic number.

It is not a de Polignac number, because 28717289 - 2²⁴ = 11940073 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (28717259) 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, 14358644 + 14358645.

It is an arithmetic number, because the mean of its divisors is an integer number (14358645).

Almost surely, 2^28717289 is an apocalyptic number.

It is an amenable number.

28717289 is a deficient number, since it is larger than the sum of its proper divisors (1).

28717289 is an equidigital number, since it uses as much as digits as its factorization.

28717289 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 112896, while the sum is 44.

The square root of 28717289 is about 5358.8514627670. The cubic root of 28717289 is about 306.2300553997.

It can be divided in two parts, 287 and 17289, that added together give a cube (17576 = 26³).

The spelling of 28717289 in words is "twenty-eight million, seven hundred seventeen thousand, two hundred eighty-nine".