66857688768 has 112 divisors (see below), whose sum is σ = 190687370720. Its totient is φ = 20551532544.

The previous prime is 66857688727. The next prime is 66857688769. The reversal of 66857688768 is 86788675866.

It is a self number, because there is not a number n which added to its sum of digits gives 66857688768.

It is not an unprimeable number, because it can be changed into a prime (66857688769) 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 15 ways as a sum of consecutive naturals, for example, 2655696 + ... + 2680752.

It is an arithmetic number, because the mean of its divisors is an integer number (1702565810).

Almost surely, 2^66857688768 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 66857688768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95343685360).

66857688768 is an abundant number, since it is smaller than the sum of its proper divisors (123829681952).

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

66857688768 is a wasteful number, since it uses less digits than its factorization.

66857688768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26154 (or 26144 counting only the distinct ones).

The product of its digits is 1300561920, while the sum is 75.

The spelling of 66857688768 in words is "sixty-six billion, eight hundred fifty-seven million, six hundred eighty-eight thousand, seven hundred sixty-eight".