668666814012 has 84 divisors (see below), whose sum is σ = 1756545347760. Its totient is φ = 222622463232.

The previous prime is 668666814007. The next prime is 668666814019. The reversal of 668666814012 is 210418666866.

It is a super-2 number, since 2×668666814012² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 668666814012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668666814019) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 2309868 + ... + 2583180.

It is an arithmetic number, because the mean of its divisors is an integer number (20911254140).

Almost surely, 2^668666814012 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 668666814012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (878272673880).

668666814012 is an abundant number, since it is smaller than the sum of its proper divisors (1087878533748).

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

668666814012 is a wasteful number, since it uses less digits than its factorization.

668666814012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274174 (or 274157 counting only the distinct ones).

The product of its (nonzero) digits is 3981312, while the sum is 54.

The spelling of 668666814012 in words is "six hundred sixty-eight billion, six hundred sixty-six million, eight hundred fourteen thousand, twelve".