6721684 has 6 divisors (see below), whose sum is σ = 11762954. Its totient is φ = 3360840.

The previous prime is 6721669. The next prime is 6721691. The reversal of 6721684 is 4861276.

6721684 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 3694084 + 3027600 = 1922^2 + 1740^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840207 + ... + 840214.

Almost surely, 2^6721684 is an apocalyptic number.

It is an amenable number.

6721684 is a deficient number, since it is larger than the sum of its proper divisors (5041270).

6721684 is a wasteful number, since it uses less digits than its factorization.

6721684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1680425 (or 1680423 counting only the distinct ones).

The product of its digits is 16128, while the sum is 34.

The square root of 6721684 is about 2592.6210675685. The cubic root of 6721684 is about 188.7235209847.

The spelling of 6721684 in words is "six million, seven hundred twenty-one thousand, six hundred eighty-four".