668624 has 40 divisors (see below), whose sum is σ = 1473120. Its totient is φ = 291200.

The previous prime is 668623. The next prime is 668671. The reversal of 668624 is 426866.

It is a happy number.

It is a congruent number.

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

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5039 + ... + 5169.

It is an arithmetic number, because the mean of its divisors is an integer number (36828).

2⁶⁶⁸⁶²⁴ 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 668624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (736560).

668624 is an abundant number, since it is smaller than the sum of its proper divisors (804496).

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

668624 is a wasteful number, since it uses less digits than its factorization.

668624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179 (or 173 counting only the distinct ones).

The product of its digits is 13824, while the sum is 32.

The square root of 668624 is about 817.6943194128. The cubic root of 668624 is about 87.4434573475.

It can be divided in two parts, 66862 and 4, that added together give a palindrome (66866).

The spelling of 668624 in words is "six hundred sixty-eight thousand, six hundred twenty-four".