68686517 has 2 divisors, whose sum is σ = 68686518. Its totient is φ = 68686516.

The previous prime is 68686469. The next prime is 68686531. The reversal of 68686517 is 71568686.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 68574961 + 111556 = 8281^2 + 334^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68686517 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68686537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34343258 + 34343259.

It is an arithmetic number, because the mean of its divisors is an integer number (34343259).

Almost surely, 2^68686517 is an apocalyptic number.

It is an amenable number.

68686517 is a deficient number, since it is larger than the sum of its proper divisors (1).

68686517 is an equidigital number, since it uses as much as digits as its factorization.

68686517 is an evil number, because the sum of its binary digits is even.

The product of its digits is 483840, while the sum is 47.

The square root of 68686517 is about 8287.7329228203. The cubic root of 68686517 is about 409.5345044159.

The spelling of 68686517 in words is "sixty-eight million, six hundred eighty-six thousand, five hundred seventeen".