66664320717312 has 640 divisors, whose sum is σ = 204560507289600. Its totient is φ = 21690799902720.

The previous prime is 66664320717271. The next prime is 66664320717347. The reversal of 66664320717312 is 21371702346666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 22682652739 + ... + 22682655677.

It is an arithmetic number, because the mean of its divisors is an integer number (319625792640).

Almost surely, 2^{66664320717312} 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 66664320717312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102280253644800).

66664320717312 is an abundant number, since it is smaller than the sum of its proper divisors (137896186572288).

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

66664320717312 is an frugal number, since it uses more digits than its factorization.

66664320717312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3456 (or 3422 counting only the distinct ones).

The product of its (nonzero) digits is 9144576, while the sum is 54.

The spelling of 66664320717312 in words is "sixty-six trillion, six hundred sixty-four billion, three hundred twenty million, seven hundred seventeen thousand, three hundred twelve".