680657 has 2 divisors, whose sum is σ = 680658. Its totient is φ = 680656.

The previous prime is 680651. The next prime is 680681. The reversal of 680657 is 756086.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 678976 + 1681 = 824^2 + 41^2 .

It is a cyclic number.

It is not a de Polignac number, because 680657 - 2⁸ = 680401 is a prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 680657.

It is not a weakly prime, because it can be changed into another prime (680651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340328 + 340329.

It is an arithmetic number, because the mean of its divisors is an integer number (340329).

2⁶⁸⁰⁶⁵⁷ is an apocalyptic number.

It is an amenable number.

680657 is a deficient number, since it is larger than the sum of its proper divisors (1).

680657 is an equidigital number, since it uses as much as digits as its factorization.

680657 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 680657 is about 825.0193937114. The cubic root of 680657 is about 87.9649050829.

Subtracting from 680657 its sum of digits (32), we obtain a square (680625 = 825²).

The spelling of 680657 in words is "six hundred eighty thousand, six hundred fifty-seven".