171208109 has 2 divisors, whose sum is σ = 171208110. Its totient is φ = 171208108.

The previous prime is 171208099. The next prime is 171208123. The reversal of 171208109 is 901802171.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 121110025 + 50098084 = 11005^2 + 7078^2 .

It is a cyclic number.

It is not a de Polignac number, because 171208109 - 2²⁰ = 170159533 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (171208409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85604054 + 85604055.

It is an arithmetic number, because the mean of its divisors is an integer number (85604055).

Almost surely, 2^171208109 is an apocalyptic number.

It is an amenable number.

171208109 is a deficient number, since it is larger than the sum of its proper divisors (1).

171208109 is an equidigital number, since it uses as much as digits as its factorization.

171208109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 29.

The square root of 171208109 is about 13084.6516575719. The cubic root of 171208109 is about 555.2749864200.

The spelling of 171208109 in words is "one hundred seventy-one million, two hundred eight thousand, one hundred nine".