680861 has 2 divisors, whose sum is σ = 680862. Its totient is φ = 680860.

The previous prime is 680857. The next prime is 680873. The reversal of 680861 is 168086.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 525625 + 155236 = 725^2 + 394^2 .

It is a cyclic number.

It is not a de Polignac number, because 680861 - 2² = 680857 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 (680831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340430 + 340431.

It is an arithmetic number, because the mean of its divisors is an integer number (340431).

2⁶⁸⁰⁸⁶¹ is an apocalyptic number.

It is an amenable number.

680861 is a deficient number, since it is larger than the sum of its proper divisors (1).

680861 is an equidigital number, since it uses as much as digits as its factorization.

680861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 680861 is about 825.1430179066. The cubic root of 680861 is about 87.9736922049.

The spelling of 680861 in words is "six hundred eighty thousand, eight hundred sixty-one".