66881086066872 has 512 divisors, whose sum is σ = 233669394432000. Its totient is φ = 17218478914560.

The previous prime is 66881086066853. The next prime is 66881086066889. The reversal of 66881086066872 is 27866068018866.

It is a happy number.

66881086066872 is a `hidden beast` number, since 6 + 6 + 8 + 8 + 1 + 0 + 8 + 606 + 6 + 8 + 7 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a self number, because there is not a number n which added to its sum of digits gives 66881086066872.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2296016404 + ... + 2296045532.

It is an arithmetic number, because the mean of its divisors is an integer number (456385536000).

Almost surely, 2^{66881086066872} 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 66881086066872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116834697216000).

66881086066872 is an abundant number, since it is smaller than the sum of its proper divisors (166788308365128).

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

66881086066872 is a wasteful number, since it uses less digits than its factorization.

66881086066872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30376 (or 30366 counting only the distinct ones).

The product of its (nonzero) digits is 445906944, while the sum is 72.

The spelling of 66881086066872 in words is "sixty-six trillion, eight hundred eighty-one billion, eighty-six million, sixty-six thousand, eight hundred seventy-two".