6687997866 has 48 divisors (see below), whose sum is σ = 15869625408. Its totient is φ = 2018764800.

The previous prime is 6687997847. The next prime is 6687997909.

6687997866 is nontrivially palindromic in base 10.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 6687997794 and 6687997803.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 14830 + ... + 116601.

It is an arithmetic number, because the mean of its divisors is an integer number (330617196).

Almost surely, 2^6687997866 is an apocalyptic number.

6687997866 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

6687997866 is an abundant number, since it is smaller than the sum of its proper divisors (9181627542).

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

6687997866 is a wasteful number, since it uses less digits than its factorization.

6687997866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131707 (or 131704 counting only the distinct ones).

The product of its digits is 329204736, while the sum is 72.

The square root of 6687997866 is about 81780.1801538735. The cubic root of 6687997866 is about 1884.0772633195.

The spelling of 6687997866 in words is "six billion, six hundred eighty-seven million, nine hundred ninety-seven thousand, eight hundred sixty-six".