6690644 has 12 divisors (see below), whose sum is σ = 11825268. Its totient is φ = 3312000.

The previous prime is 6690643. The next prime is 6690647. The reversal of 6690644 is 4460966.

It can be written as a sum of positive squares in 2 ways, for example, as 3378244 + 3312400 = 1838^2 + 1820^2 .

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6690643) 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 3 ways as a sum of consecutive naturals, for example, 7877 + ... + 8684.

It is an arithmetic number, because the mean of its divisors is an integer number (985439).

Almost surely, 2^6690644 is an apocalyptic number.

It is an amenable number.

6690644 is a deficient number, since it is larger than the sum of its proper divisors (5134624).

6690644 is a wasteful number, since it uses less digits than its factorization.

6690644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16666 (or 16664 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 35.

The square root of 6690644 is about 2586.6279206720. The cubic root of 6690644 is about 188.4325711542.

The spelling of 6690644 in words is "six million, six hundred ninety thousand, six hundred forty-four".