6668781 has 16 divisors (see below), whose sum is σ = 10604544. Its totient is φ = 3644784.

The previous prime is 6668759. The next prime is 6668789. The reversal of 6668781 is 1878666.

It is not a de Polignac number, because 6668781 - 2⁹ = 6668269 is a prime.

It is a super-2 number, since 2×6668781² = 88945280051922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6668789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6421 + ... + 7386.

It is an arithmetic number, because the mean of its divisors is an integer number (662784).

Almost surely, 2^6668781 is an apocalyptic number.

It is an amenable number.

6668781 is a deficient number, since it is larger than the sum of its proper divisors (3935763).

6668781 is a wasteful number, since it uses less digits than its factorization.

6668781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13840.

The product of its digits is 96768, while the sum is 42.

The square root of 6668781 is about 2582.3983039028. The cubic root of 6668781 is about 188.2271003116.

The spelling of 6668781 in words is "six million, six hundred sixty-eight thousand, seven hundred eighty-one".