217109117 has 2 divisors, whose sum is σ = 217109118. Its totient is φ = 217109116.

The previous prime is 217109111. The next prime is 217109119. The reversal of 217109117 is 711901712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 122124601 + 94984516 = 11051^2 + 9746^2 .

It is a cyclic number.

It is not a de Polignac number, because 217109117 - 2⁸ = 217108861 is a prime.

Together with 217109119, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 217109117.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217109111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108554558 + 108554559.

It is an arithmetic number, because the mean of its divisors is an integer number (108554559).

Almost surely, 2^217109117 is an apocalyptic number.

It is an amenable number.

217109117 is a deficient number, since it is larger than the sum of its proper divisors (1).

217109117 is an equidigital number, since it uses as much as digits as its factorization.

217109117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 882, while the sum is 29.

The square root of 217109117 is about 14734.6230694918. The cubic root of 217109117 is about 601.0252074370.

The spelling of 217109117 in words is "two hundred seventeen million, one hundred nine thousand, one hundred seventeen".