668579 has 2 divisors, whose sum is σ = 668580. Its totient is φ = 668578.

The previous prime is 668567. The next prime is 668581. The reversal of 668579 is 975866.

It is a happy number.

668579 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-668579 is a prime.

It is a Sophie Germain prime.

Together with 668581, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (668509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334289 + 334290.

It is an arithmetic number, because the mean of its divisors is an integer number (334290).

2⁶⁶⁸⁵⁷⁹ is an apocalyptic number.

668579 is a deficient number, since it is larger than the sum of its proper divisors (1).

668579 is an equidigital number, since it uses as much as digits as its factorization.

668579 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720, while the sum is 41.

The square root of 668579 is about 817.6668025547. Note that the first 3 decimals coincide. The cubic root of 668579 is about 87.4414955853.

It can be divided in two parts, 66857 and 9, that added together give a palindrome (66866).

The spelling of 668579 in words is "six hundred sixty-eight thousand, five hundred seventy-nine".