6661686858816 has 280 divisors, whose sum is σ = 19606744936800. Its totient is φ = 1995936081920.

The previous prime is 6661686858797. The next prime is 6661686858829. The reversal of 6661686858816 is 6188586861666.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 250172095 + ... + 250198721.

It is an arithmetic number, because the mean of its divisors is an integer number (70024089060).

Almost surely, 2^{6661686858816} is an apocalyptic number.

6661686858816 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 6661686858816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9803372468400).

6661686858816 is an abundant number, since it is smaller than the sum of its proper divisors (12945058077984).

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

6661686858816 is an equidigital number, since it uses as much as digits as its factorization.

6661686858816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26775 (or 26732 counting only the distinct ones).

The product of its digits is 955514880, while the sum is 75.

The spelling of 6661686858816 in words is "six trillion, six hundred sixty-one billion, six hundred eighty-six million, eight hundred fifty-eight thousand, eight hundred sixteen".