6688344438866 has 4 divisors (see below), whose sum is σ = 10032516658302. Its totient is φ = 3344172219432.

The previous prime is 6688344438833. The next prime is 6688344438883.

6688344438866 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 3493456308241 + 3194888130625 = 1869079^2 + 1787425^2 .

It is a super-2 number, since 2×6688344438866² (a number of 26 digits) contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 6688344438793 and 6688344438802.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 1672086109715 + ... + 1672086109718.

Almost surely, 2^{6688344438866} is an apocalyptic number.

6688344438866 is a deficient number, since it is larger than the sum of its proper divisors (3344172219436).

6688344438866 is a wasteful number, since it uses less digits than its factorization.

6688344438866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3344172219435.

The product of its digits is 3057647616, while the sum is 74.

The spelling of 6688344438866 in words is "six trillion, six hundred eighty-eight billion, three hundred forty-four million, four hundred thirty-eight thousand, eight hundred sixty-six".