6691881966 has 128 divisors (see below), whose sum is σ = 17973964800. Its totient is φ = 1608284160.

The previous prime is 6691881961. The next prime is 6691881967.

6691881966 is nontrivially palindromic in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6691881961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 368590 + ... + 386318.

It is an arithmetic number, because the mean of its divisors is an integer number (140421600).

Almost surely, 2^6691881966 is an apocalyptic number.

6691881966 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 6691881966, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8986982400).

6691881966 is an abundant number, since it is smaller than the sum of its proper divisors (11282082834).

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

6691881966 is a wasteful number, since it uses less digits than its factorization.

6691881966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17814.

The product of its digits is 6718464, while the sum is 60.

The square root of 6691881966 is about 81803.9239034412. The cubic root of 6691881966 is about 1884.4419229408.

The spelling of 6691881966 in words is "six billion, six hundred ninety-one million, eight hundred eighty-one thousand, nine hundred sixty-six".