668279 has 4 divisors (see below), whose sum is σ = 674520. Its totient is φ = 662040.

The previous prime is 668273. The next prime is 668303. The reversal of 668279 is 972866.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 972866 = 2 ⋅486433.

It is a cyclic number.

It is not a de Polignac number, because 668279 - 2¹⁶ = 602743 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668273) 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 in 3 ways as a sum of consecutive naturals, for example, 2957 + ... + 3174.

It is an arithmetic number, because the mean of its divisors is an integer number (168630).

2⁶⁶⁸²⁷⁹ is an apocalyptic number.

668279 is a deficient number, since it is larger than the sum of its proper divisors (6241).

668279 is a wasteful number, since it uses less digits than its factorization.

668279 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6240.

The product of its digits is 36288, while the sum is 38.

The square root of 668279 is about 817.4833331634. The cubic root of 668279 is about 87.4284149205.

It can be divided in two parts, 6682 and 79, that multiplied together give a triangular number (527878 = T₁₀₂₇).

The spelling of 668279 in words is "six hundred sixty-eight thousand, two hundred seventy-nine".