668221602012 has 72 divisors (see below), whose sum is σ = 1717321438560. Its totient is φ = 219023291520.

The previous prime is 668221601987. The next prime is 668221602023. The reversal of 668221602012 is 210206122866.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7560814 + ... + 7648682.

Almost surely, 2^668221602012 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 668221602012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (858660719280).

668221602012 is an abundant number, since it is smaller than the sum of its proper divisors (1049099836548).

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

668221602012 is a wasteful number, since it uses less digits than its factorization.

668221602012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91403 (or 91398 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

Adding to 668221602012 its reverse (210206122866), we get a palindrome (878427724878).

The spelling of 668221602012 in words is "six hundred sixty-eight billion, two hundred twenty-one million, six hundred two thousand, twelve".