686436281 has 2 divisors, whose sum is σ = 686436282. Its totient is φ = 686436280.

The previous prime is 686436277. The next prime is 686436323. The reversal of 686436281 is 182634686.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 629207056 + 57229225 = 25084^2 + 7565^2 .

It is a cyclic number.

It is not a de Polignac number, because 686436281 - 2² = 686436277 is a prime.

It is a super-2 number, since 2×686436281² = 942389535746221922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (686432281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343218140 + 343218141.

It is an arithmetic number, because the mean of its divisors is an integer number (343218141).

Almost surely, 2^686436281 is an apocalyptic number.

It is an amenable number.

686436281 is a deficient number, since it is larger than the sum of its proper divisors (1).

686436281 is an equidigital number, since it uses as much as digits as its factorization.

686436281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 331776, while the sum is 44.

The square root of 686436281 is about 26199.9290266214. The cubic root of 686436281 is about 882.1316611606.

The spelling of 686436281 in words is "six hundred eighty-six million, four hundred thirty-six thousand, two hundred eighty-one".