217364539391 has 2 divisors, whose sum is σ = 217364539392. Its totient is φ = 217364539390.

The previous prime is 217364539367. The next prime is 217364539393. The reversal of 217364539391 is 193935463712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 217364539391 - 2³⁴ = 200184670207 is a prime.

Together with 217364539393, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217364539393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108682269695 + 108682269696.

It is an arithmetic number, because the mean of its divisors is an integer number (108682269696).

Almost surely, 2^217364539391 is an apocalyptic number.

217364539391 is a deficient number, since it is larger than the sum of its proper divisors (1).

217364539391 is an equidigital number, since it uses as much as digits as its factorization.

217364539391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3674160, while the sum is 53.

The spelling of 217364539391 in words is "two hundred seventeen billion, three hundred sixty-four million, five hundred thirty-nine thousand, three hundred ninety-one".