668726 has 4 divisors (see below), whose sum is σ = 1003092. Its totient is φ = 334362.

The previous prime is 668719. The next prime is 668737. The reversal of 668726 is 627866.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 627866 = 2 ⋅313933.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 167180 + ... + 167183.

It is an arithmetic number, because the mean of its divisors is an integer number (250773).

2⁶⁶⁸⁷²⁶ is an apocalyptic number.

668726 is a deficient number, since it is larger than the sum of its proper divisors (334366).

668726 is a wasteful number, since it uses less digits than its factorization.

668726 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 334365.

The product of its digits is 24192, while the sum is 35.

The square root of 668726 is about 817.7566875300. The cubic root of 668726 is about 87.4479036826.

The spelling of 668726 in words is "six hundred sixty-eight thousand, seven hundred twenty-six".