668340 has 72 divisors (see below), whose sum is σ = 2096640. Its totient is φ = 172224.

The previous prime is 668303. The next prime is 668347. The reversal of 668340 is 43866.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668347) by changing a digit.

668340 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 23 ways as a sum of consecutive naturals, for example, 8421 + ... + 8499.

It is an arithmetic number, because the mean of its divisors is an integer number (29120).

2⁶⁶⁸³⁴⁰ is an apocalyptic number.

668340 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1048320).

668340 is an abundant number, since it is smaller than the sum of its proper divisors (1428300).

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

668340 is a wasteful number, since it uses less digits than its factorization.

668340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141 (or 136 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 668340 is about 817.5206419412. The cubic root of 668340 is about 87.4310749727.

The spelling of 668340 in words is "six hundred sixty-eight thousand, three hundred forty".