28691617 has 2 divisors, whose sum is σ = 28691618. Its totient is φ = 28691616.

The previous prime is 28691609. The next prime is 28691629. The reversal of 28691617 is 71619682.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19395216 + 9296401 = 4404^2 + 3049^2 .

It is a cyclic number.

It is not a de Polignac number, because 28691617 - 2³ = 28691609 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28691617.

It is not a weakly prime, because it can be changed into another prime (28691657) 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, 14345808 + 14345809.

It is an arithmetic number, because the mean of its divisors is an integer number (14345809).

Almost surely, 2^28691617 is an apocalyptic number.

It is an amenable number.

28691617 is a deficient number, since it is larger than the sum of its proper divisors (1).

28691617 is an equidigital number, since it uses as much as digits as its factorization.

28691617 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 40.

The square root of 28691617 is about 5356.4556378262. The cubic root of 28691617 is about 306.1387761037.

The spelling of 28691617 in words is "twenty-eight million, six hundred ninety-one thousand, six hundred seventeen".