6678649 has 4 divisors (see below), whose sum is σ = 6753780. Its totient is φ = 6603520.

The previous prime is 6678647. The next prime is 6678667. The reversal of 6678649 is 9468766.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9468766 = 2 ⋅4734383.

It can be written as a sum of positive squares in 2 ways, for example, as 3873024 + 2805625 = 1968^2 + 1675^2 .

It is a cyclic number.

It is not a de Polignac number, because 6678649 - 2¹ = 6678647 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6678599 and 6678608.

It is not an unprimeable number, because it can be changed into a prime (6678641) 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 3 ways as a sum of consecutive naturals, for example, 37432 + ... + 37609.

It is an arithmetic number, because the mean of its divisors is an integer number (1688445).

Almost surely, 2^6678649 is an apocalyptic number.

It is an amenable number.

6678649 is a deficient number, since it is larger than the sum of its proper divisors (75131).

6678649 is an equidigital number, since it uses as much as digits as its factorization.

6678649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75130.

The product of its digits is 435456, while the sum is 46.

The square root of 6678649 is about 2584.3082246512. The cubic root of 6678649 is about 188.3198963621.

It can be divided in two parts, 667 and 8649, that added together give a triangular number (9316 = T₁₃₆).

The spelling of 6678649 in words is "six million, six hundred seventy-eight thousand, six hundred forty-nine".