171705205217 has 16 divisors (see below), whose sum is σ = 211365165312. Its totient is φ = 135831729600.

The previous prime is 171705205207. The next prime is 171705205249. The reversal of 171705205217 is 712502507171.

It is a happy number.

It is not a de Polignac number, because 171705205217 - 2¹⁶ = 171705139681 is a prime.

It is a super-2 number, since 2×171705205217² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (171705205207) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 393092 + ... + 705642.

It is an arithmetic number, because the mean of its divisors is an integer number (13210322832).

Almost surely, 2^171705205217 is an apocalyptic number.

It is an amenable number.

171705205217 is a deficient number, since it is larger than the sum of its proper divisors (39659960095).

171705205217 is a wasteful number, since it uses less digits than its factorization.

171705205217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 318608.

The product of its (nonzero) digits is 34300, while the sum is 38.

The spelling of 171705205217 in words is "one hundred seventy-one billion, seven hundred five million, two hundred five thousand, two hundred seventeen".