28605217 has 2 divisors, whose sum is σ = 28605218. Its totient is φ = 28605216.

The previous prime is 28605209. The next prime is 28605221. The reversal of 28605217 is 71250682.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25796241 + 2808976 = 5079^2 + 1676^2 .

It is a cyclic number.

It is not a de Polignac number, because 28605217 - 2³ = 28605209 is a prime.

It is not a weakly prime, because it can be changed into another prime (28605257) 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, 14302608 + 14302609.

It is an arithmetic number, because the mean of its divisors is an integer number (14302609).

Almost surely, 2^28605217 is an apocalyptic number.

It is an amenable number.

28605217 is a deficient number, since it is larger than the sum of its proper divisors (1).

28605217 is an equidigital number, since it uses as much as digits as its factorization.

28605217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6720, while the sum is 31.

The square root of 28605217 is about 5348.3845224516. The cubic root of 28605217 is about 305.8311719108.

Adding to 28605217 its reverse (71250682), we get a palindrome (99855899).

The spelling of 28605217 in words is "twenty-eight million, six hundred five thousand, two hundred seventeen".