668140 has 24 divisors (see below), whose sum is σ = 1531152. Its totient is φ = 242880.

The previous prime is 668111. The next prime is 668141. The reversal of 668140 is 41866.

668140 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×668140² = 892822119200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (668141) by changing a digit.

668140 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 7 ways as a sum of consecutive naturals, for example, 1299 + ... + 1738.

It is an arithmetic number, because the mean of its divisors is an integer number (63798).

2⁶⁶⁸¹⁴⁰ is an apocalyptic number.

It is an amenable number.

668140 is an abundant number, since it is smaller than the sum of its proper divisors (863012).

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

668140 is a wasteful number, since it uses less digits than its factorization.

668140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3057 (or 3055 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 668140 is about 817.3983117183. The cubic root of 668140 is about 87.4223528854.

It can be divided in two parts, 668 and 140, that added together give a palindrome (808).

The spelling of 668140 in words is "six hundred sixty-eight thousand, one hundred forty".