686856361 has 2 divisors, whose sum is σ = 686856362. Its totient is φ = 686856360.

The previous prime is 686856353. The next prime is 686856377. The reversal of 686856361 is 163658686.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 368448025 + 318408336 = 19195^2 + 17844^2 .

It is a cyclic number.

It is not a de Polignac number, because 686856361 - 2³ = 686856353 is a prime.

It is not a weakly prime, because it can be changed into another prime (686856301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343428180 + 343428181.

It is an arithmetic number, because the mean of its divisors is an integer number (343428181).

Almost surely, 2^686856361 is an apocalyptic number.

It is an amenable number.

686856361 is a deficient number, since it is larger than the sum of its proper divisors (1).

686856361 is an equidigital number, since it uses as much as digits as its factorization.

686856361 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1244160, while the sum is 49.

The square root of 686856361 is about 26207.9446160892. The cubic root of 686856361 is about 882.3115711839.

The spelling of 686856361 in words is "six hundred eighty-six million, eight hundred fifty-six thousand, three hundred sixty-one".