217505706667 has 2 divisors, whose sum is σ = 217505706668. Its totient is φ = 217505706666.

The previous prime is 217505706653. The next prime is 217505706679. The reversal of 217505706667 is 766607505712.

It is a happy number.

217505706667 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-217505706667 is a prime.

It is a super-2 number, since 2×217505706667² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (217505706637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108752853333 + 108752853334.

It is an arithmetic number, because the mean of its divisors is an integer number (108752853334).

Almost surely, 2^217505706667 is an apocalyptic number.

217505706667 is a deficient number, since it is larger than the sum of its proper divisors (1).

217505706667 is an equidigital number, since it uses as much as digits as its factorization.

217505706667 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3704400, while the sum is 52.

The spelling of 217505706667 in words is "two hundred seventeen billion, five hundred five million, seven hundred six thousand, six hundred sixty-seven".