686666711 has 2 divisors, whose sum is σ = 686666712. Its totient is φ = 686666710.

The previous prime is 686666671. The next prime is 686666713. The reversal of 686666711 is 117666686.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-686666711 is a prime.

It is a super-2 number, since 2×686666711² = 943022343991115042, which contains 22 as substring.

Together with 686666713, 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 (686666713) 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, 343333355 + 343333356.

It is an arithmetic number, because the mean of its divisors is an integer number (343333356).

Almost surely, 2^686666711 is an apocalyptic number.

686666711 is a deficient number, since it is larger than the sum of its proper divisors (1).

686666711 is an equidigital number, since it uses as much as digits as its factorization.

686666711 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 435456, while the sum is 47.

The square root of 686666711 is about 26204.3261886277. The cubic root of 686666711 is about 882.2303577978.

The spelling of 686666711 in words is "six hundred eighty-six million, six hundred sixty-six thousand, seven hundred eleven".