217185072197 has 2 divisors, whose sum is σ = 217185072198. Its totient is φ = 217185072196.

The previous prime is 217185072163. The next prime is 217185072311. The reversal of 217185072197 is 791270581712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 214363444036 + 2821628161 = 462994^2 + 53119^2 .

It is a cyclic number.

It is not a de Polignac number, because 217185072197 - 2³² = 212890104901 is a prime.

It is a super-2 number, since 2×217185072197² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217185072397) 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, 108592536098 + 108592536099.

It is an arithmetic number, because the mean of its divisors is an integer number (108592536099).

Almost surely, 2^217185072197 is an apocalyptic number.

It is an amenable number.

217185072197 is a deficient number, since it is larger than the sum of its proper divisors (1).

217185072197 is an equidigital number, since it uses as much as digits as its factorization.

217185072197 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 493920, while the sum is 50.

The spelling of 217185072197 in words is "two hundred seventeen billion, one hundred eighty-five million, seventy-two thousand, one hundred ninety-seven".