66681686016 has 144 divisors (see below), whose sum is σ = 210097676880. Its totient is φ = 20206510080.

The previous prime is 66681685991. The next prime is 66681686059. The reversal of 66681686016 is 61068618666.

It is a tau number, because it is divible by the number of its divisors (144).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 38311 + ... + 367193.

It is an arithmetic number, because the mean of its divisors is an integer number (1459011645).

Almost surely, 2^66681686016 is an apocalyptic number.

66681686016 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66681686016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105048838440).

66681686016 is an abundant number, since it is smaller than the sum of its proper divisors (143415990864).

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

66681686016 is a wasteful number, since it uses less digits than its factorization.

66681686016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328922 (or 328899 counting only the distinct ones).

The product of its (nonzero) digits is 2985984, while the sum is 54.

The spelling of 66681686016 in words is "sixty-six billion, six hundred eighty-one million, six hundred eighty-six thousand, sixteen".