205120718171 has 2 divisors, whose sum is σ = 205120718172. Its totient is φ = 205120718170.

The previous prime is 205120718167. The next prime is 205120718197. The reversal of 205120718171 is 171817021502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 205120718171 - 2² = 205120718167 is a prime.

It is not a weakly prime, because it can be changed into another prime (205120718371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102560359085 + 102560359086.

It is an arithmetic number, because the mean of its divisors is an integer number (102560359086).

Almost surely, 2^205120718171 is an apocalyptic number.

205120718171 is a deficient number, since it is larger than the sum of its proper divisors (1).

205120718171 is an equidigital number, since it uses as much as digits as its factorization.

205120718171 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7840, while the sum is 35.

Adding to 205120718171 its reverse (171817021502), we get a palindrome (376937739673).

The spelling of 205120718171 in words is "two hundred five billion, one hundred twenty million, seven hundred eighteen thousand, one hundred seventy-one".