680509 has 2 divisors, whose sum is σ = 680510. Its totient is φ = 680508.

The previous prime is 680507. The next prime is 680531. The reversal of 680509 is 905086.

680509 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 558009 + 122500 = 747^2 + 350^2 .

It is a cyclic number.

It is not a de Polignac number, because 680509 - 2¹ = 680507 is a prime.

Together with 680507, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (680503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340254 + 340255.

It is an arithmetic number, because the mean of its divisors is an integer number (340255).

2⁶⁸⁰⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

680509 is a deficient number, since it is larger than the sum of its proper divisors (1).

680509 is an equidigital number, since it uses as much as digits as its factorization.

680509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 680509 is about 824.9296939740. The cubic root of 680509 is about 87.9585290131.

The spelling of 680509 in words is "six hundred eighty thousand, five hundred nine".