668723 has 4 divisors (see below), whose sum is σ = 729528. Its totient is φ = 607920.

The previous prime is 668719. The next prime is 668737. The reversal of 668723 is 327866.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 668723 - 2² = 668719 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a plaindrome in base 14.

It is a self number, because there is not a number n which added to its sum of digits gives 668723.

It is not an unprimeable number, because it can be changed into a prime (668713) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30386 + ... + 30407.

It is an arithmetic number, because the mean of its divisors is an integer number (182382).

2⁶⁶⁸⁷²³ is an apocalyptic number.

668723 is a deficient number, since it is larger than the sum of its proper divisors (60805).

668723 is a wasteful number, since it uses less digits than its factorization.

668723 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60804.

The product of its digits is 12096, while the sum is 32.

The square root of 668723 is about 817.7548532415. The cubic root of 668723 is about 87.4477729145.

The spelling of 668723 in words is "six hundred sixty-eight thousand, seven hundred twenty-three".