668878812 has 144 divisors (see below), whose sum is σ = 2076256000. Its totient is φ = 180986400.

The previous prime is 668878789. The next prime is 668878817. The reversal of 668878812 is 218878866.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668878817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 233187 + ... + 236037.

Almost surely, 2^668878812 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 668878812, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1038128000).

668878812 is an abundant number, since it is smaller than the sum of its proper divisors (1407377188).

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

668878812 is a wasteful number, since it uses less digits than its factorization.

668878812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2901 (or 2882 counting only the distinct ones).

The product of its digits is 2064384, while the sum is 54.

The square root of 668878812 is about 25862.6915072658. The cubic root of 668878812 is about 874.5456414408.

Adding to 668878812 its sum of digits (54), we get a palindrome (668878866).

The spelling of 668878812 in words is "six hundred sixty-eight million, eight hundred seventy-eight thousand, eight hundred twelve".