66468761856 has 648 divisors, whose sum is σ = 240458531040. Its totient is φ = 17541070848.

The previous prime is 66468761819. The next prime is 66468761857. The reversal of 66468761856 is 65816786466.

66468761856 is a `hidden beast` number, since 6 + 6 + 4 + 6 + 8 + 7 + 618 + 5 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a junction number, because it is equal to n+sod(n) for n = 66468761793 and 66468761802.

It is not an unprimeable number, because it can be changed into a prime (66468761857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 113234395 + ... + 113234981.

It is an arithmetic number, because the mean of its divisors is an integer number (371077980).

Almost surely, 2^66468761856 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 66468761856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120229265520).

66468761856 is an abundant number, since it is smaller than the sum of its proper divisors (173989769184).

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

66468761856 is a wasteful number, since it uses less digits than its factorization.

66468761856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 699 (or 675 counting only the distinct ones).

The product of its digits is 69672960, while the sum is 63.

The spelling of 66468761856 in words is "sixty-six billion, four hundred sixty-eight million, seven hundred sixty-one thousand, eight hundred fifty-six".