1686317039861 has 2 divisors, whose sum is σ = 1686317039862. Its totient is φ = 1686317039860.

The previous prime is 1686317039851. The next prime is 1686317039863. The reversal of 1686317039861 is 1689307136861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1677685515025 + 8631524836 = 1295255^2 + 92906^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1686317039861 is a prime.

Together with 1686317039863, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1686317039861.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1686317039863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 843158519930 + 843158519931.

It is an arithmetic number, because the mean of its divisors is an integer number (843158519931).

Almost surely, 2^{1686317039861} is an apocalyptic number.

It is an amenable number.

1686317039861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1686317039861 is an equidigital number, since it uses as much as digits as its factorization.

1686317039861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7838208, while the sum is 59.

The spelling of 1686317039861 in words is "one trillion, six hundred eighty-six billion, three hundred seventeen million, thirty-nine thousand, eight hundred sixty-one".