6776721 has 24 divisors (see below), whose sum is σ = 11256960. Its totient is φ = 3848256.

The previous prime is 6776717. The next prime is 6776741. The reversal of 6776721 is 1276776.

6776721 is a nontrivial binomial coefficient, being equal to C(3682, 2).

It is not a de Polignac number, because 6776721 - 2² = 6776717 is a prime.

6776721 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (6776741) 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 23 ways as a sum of consecutive naturals, for example, 16365 + ... + 16773.

It is an arithmetic number, because the mean of its divisors is an integer number (469040).

Almost surely, 2^6776721 is an apocalyptic number.

6776721 is the 3681-st triangular number and also the 1841-st hexagonal number.

It is an amenable number.

6776721 is a deficient number, since it is larger than the sum of its proper divisors (4480239).

6776721 is a wasteful number, since it uses less digits than its factorization.

6776721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 685 (or 682 counting only the distinct ones).

The product of its digits is 24696, while the sum is 36.

The square root of 6776721 is about 2603.2135909295. The cubic root of 6776721 is about 189.2372095079.

Subtracting from 6776721 its reverse (1276776), we obtain a palindrome (5499945).

The spelling of 6776721 in words is "six million, seven hundred seventy-six thousand, seven hundred twenty-one".