668879 has 2 divisors, whose sum is σ = 668880. Its totient is φ = 668878.

The previous prime is 668873. The next prime is 668903. The reversal of 668879 is 978866.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 668879 - 2⁸ = 668623 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 (668873) 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, 334439 + 334440.

It is an arithmetic number, because the mean of its divisors is an integer number (334440).

2⁶⁶⁸⁸⁷⁹ is an apocalyptic number.

668879 is a deficient number, since it is larger than the sum of its proper divisors (1).

668879 is an equidigital number, since it uses as much as digits as its factorization.

668879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 44.

The square root of 668879 is about 817.8502307880. The cubic root of 668879 is about 87.4545723376.

The spelling of 668879 in words is "six hundred sixty-eight thousand, eight hundred seventy-nine".