668628 has 48 divisors (see below), whose sum is σ = 1787520. Its totient is φ = 216000.

The previous prime is 668623. The next prime is 668671. The reversal of 668628 is 826866.

668628 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 668592 and 668601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668623) by changing a digit.

668628 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4353 + ... + 4503.

It is an arithmetic number, because the mean of its divisors is an integer number (37240).

2⁶⁶⁸⁶²⁸ 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 668628, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (893760).

668628 is an abundant number, since it is smaller than the sum of its proper divisors (1118892).

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

668628 is a wasteful number, since it uses less digits than its factorization.

668628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205 (or 197 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 668628 is about 817.6967653110. The cubic root of 668628 is about 87.4436317221.

It can be divided in two parts, 668 and 628, that added together give a 4-th power (1296 = 6⁴).

The spelling of 668628 in words is "six hundred sixty-eight thousand, six hundred twenty-eight".