679909 has 2 divisors, whose sum is σ = 679910. Its totient is φ = 679908.

The previous prime is 679907. The next prime is 679919. The reversal of 679909 is 909976.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 675684 + 4225 = 822^2 + 65^2 .

It is a cyclic number.

It is not a de Polignac number, because 679909 - 2¹ = 679907 is a prime.

Together with 679907, it forms a pair of twin primes.

It is a Chen prime.

679909 is a lucky number.

It is a plaindrome in base 14.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (679907) 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, 339954 + 339955.

It is an arithmetic number, because the mean of its divisors is an integer number (339955).

2⁶⁷⁹⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

679909 is a deficient number, since it is larger than the sum of its proper divisors (1).

679909 is an equidigital number, since it uses as much as digits as its factorization.

679909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30618, while the sum is 40.

The square root of 679909 is about 824.5659464227. The cubic root of 679909 is about 87.9326706064.

The spelling of 679909 in words is "six hundred seventy-nine thousand, nine hundred nine".