6688549 has 6 divisors (see below), whose sum is σ = 7780614. Its totient is φ = 5733000.

The previous prime is 6688537. The next prime is 6688559. The reversal of 6688549 is 9458866.

6688549 is digitally balanced in base 3, 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., 4708900 + 1979649 = 2170^2 + 1407^2 .

It is not a de Polignac number, because 6688549 - 2⁷ = 6688421 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6688499 and 6688508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6688519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 68202 + ... + 68299.

It is an arithmetic number, because the mean of its divisors is an integer number (1296769).

Almost surely, 2^6688549 is an apocalyptic number.

It is an amenable number.

6688549 is a deficient number, since it is larger than the sum of its proper divisors (1092065).

6688549 is a wasteful number, since it uses less digits than its factorization.

6688549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136515 (or 136508 counting only the distinct ones).

The product of its digits is 414720, while the sum is 46.

The square root of 6688549 is about 2586.2229215595. Note that the first 3 decimals coincide. The cubic root of 6688549 is about 188.4129015256.

The spelling of 6688549 in words is "six million, six hundred eighty-eight thousand, five hundred forty-nine".