687685676675717 has 2 divisors, whose sum is σ = 687685676675718. Its totient is φ = 687685676675716.

The previous prime is 687685676675603. The next prime is 687685676675719. The reversal of 687685676675717 is 717576676586786.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 426425845306561 + 261259831369156 = 20650081^2 + 16163534^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-687685676675717 is a prime.

Together with 687685676675719, 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 (687685676675719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343842838337858 + 343842838337859.

It is an arithmetic number, because the mean of its divisors is an integer number (343842838337859).

Almost surely, 2^{687685676675717} is an apocalyptic number.

It is an amenable number.

687685676675717 is a deficient number, since it is larger than the sum of its proper divisors (1).

687685676675717 is an equidigital number, since it uses as much as digits as its factorization.

687685676675717 is an evil number, because the sum of its binary digits is even.

The product of its digits is 209105971200, while the sum is 92.

The spelling of 687685676675717 in words is "six hundred eighty-seven trillion, six hundred eighty-five billion, six hundred seventy-six million, six hundred seventy-five thousand, seven hundred seventeen".