668868140 has 12 divisors (see below), whose sum is σ = 1404623136. Its totient is φ = 267547248.

The previous prime is 668868133. The next prime is 668868149. The reversal of 668868140 is 41868866.

It is not an unprimeable number, because it can be changed into a prime (668868149) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16721684 + ... + 16721723.

It is an arithmetic number, because the mean of its divisors is an integer number (117051928).

Almost surely, 2^668868140 is an apocalyptic number.

It is an amenable number.

668868140 is an abundant number, since it is smaller than the sum of its proper divisors (735754996).

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

668868140 is a wasteful number, since it uses less digits than its factorization.

668868140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33443416 (or 33443414 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 47.

The square root of 668868140 is about 25862.4851860760. The cubic root of 668868140 is about 874.5409902740.

The spelling of 668868140 in words is "six hundred sixty-eight million, eight hundred sixty-eight thousand, one hundred forty".