217165493 has 2 divisors, whose sum is σ = 217165494. Its totient is φ = 217165492.

The previous prime is 217165457. The next prime is 217165513. The reversal of 217165493 is 394561712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 214534609 + 2630884 = 14647^2 + 1622^2 .

It is a cyclic number.

It is not a de Polignac number, because 217165493 - 2⁸ = 217165237 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217165423) 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, 108582746 + 108582747.

It is an arithmetic number, because the mean of its divisors is an integer number (108582747).

Almost surely, 2^217165493 is an apocalyptic number.

It is an amenable number.

217165493 is a deficient number, since it is larger than the sum of its proper divisors (1).

217165493 is an equidigital number, since it uses as much as digits as its factorization.

217165493 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 45360, while the sum is 38.

The square root of 217165493 is about 14736.5359905237. The cubic root of 217165493 is about 601.0772250049.

The spelling of 217165493 in words is "two hundred seventeen million, one hundred sixty-five thousand, four hundred ninety-three".