169808728217 has 2 divisors, whose sum is σ = 169808728218. Its totient is φ = 169808728216.

The previous prime is 169808728147. The next prime is 169808728283. The reversal of 169808728217 is 712827808961.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 144838091776 + 24970636441 = 380576^2 + 158021^2 .

It is a cyclic number.

It is not a de Polignac number, because 169808728217 - 2⁸ = 169808727961 is a prime.

It is not a weakly prime, because it can be changed into another prime (169808728517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84904364108 + 84904364109.

It is an arithmetic number, because the mean of its divisors is an integer number (84904364109).

Almost surely, 2^169808728217 is an apocalyptic number.

It is an amenable number.

169808728217 is a deficient number, since it is larger than the sum of its proper divisors (1).

169808728217 is an equidigital number, since it uses as much as digits as its factorization.

169808728217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5419008, while the sum is 59.

The spelling of 169808728217 in words is "one hundred sixty-nine billion, eight hundred eight million, seven hundred twenty-eight thousand, two hundred seventeen".