668712 has 64 divisors (see below), whose sum is σ = 1944000. Its totient is φ = 189440.

The previous prime is 668699. The next prime is 668713. The reversal of 668712 is 217866.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 668712.

It is a congruent number.

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

668712 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4414 + ... + 4562.

It is an arithmetic number, because the mean of its divisors is an integer number (30375).

2⁶⁶⁸⁷¹² is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (972000).

668712 is an abundant number, since it is smaller than the sum of its proper divisors (1275288).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

668712 is a wasteful number, since it uses less digits than its factorization.

668712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186 (or 182 counting only the distinct ones).

The product of its digits is 4032, while the sum is 30.

The square root of 668712 is about 817.7481274818. The cubic root of 668712 is about 87.4472934281.

It can be divided in two parts, 66 and 8712, that added together give a palindrome (8778).

The spelling of 668712 in words is "six hundred sixty-eight thousand, seven hundred twelve".