217875195749 has 2 divisors, whose sum is σ = 217875195750. Its totient is φ = 217875195748.

The previous prime is 217875195673. The next prime is 217875195757. The reversal of 217875195749 is 947591578712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 186291508225 + 31583687524 = 431615^2 + 177718^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-217875195749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217875195149) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108937597874 + 108937597875.

It is an arithmetic number, because the mean of its divisors is an integer number (108937597875).

Almost surely, 2^217875195749 is an apocalyptic number.

It is an amenable number.

217875195749 is a deficient number, since it is larger than the sum of its proper divisors (1).

217875195749 is an equidigital number, since it uses as much as digits as its factorization.

217875195749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 44452800, while the sum is 65.

The spelling of 217875195749 in words is "two hundred seventeen billion, eight hundred seventy-five million, one hundred ninety-five thousand, seven hundred forty-nine".