217608745609 has 2 divisors, whose sum is σ = 217608745610. Its totient is φ = 217608745608.

The previous prime is 217608745591. The next prime is 217608745639. The reversal of 217608745609 is 906547806712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 207808339600 + 9800406009 = 455860^2 + 98997^2 .

It is a cyclic number.

It is not a de Polignac number, because 217608745609 - 2¹⁹ = 217608221321 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 217608745609.

It is not a weakly prime, because it can be changed into another prime (217608745639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108804372804 + 108804372805.

It is an arithmetic number, because the mean of its divisors is an integer number (108804372805).

Almost surely, 2^217608745609 is an apocalyptic number.

It is an amenable number.

217608745609 is a deficient number, since it is larger than the sum of its proper divisors (1).

217608745609 is an equidigital number, since it uses as much as digits as its factorization.

217608745609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5080320, while the sum is 55.

The spelling of 217608745609 in words is "two hundred seventeen billion, six hundred eight million, seven hundred forty-five thousand, six hundred nine".