6640444 has 6 divisors (see below), whose sum is σ = 11620784. Its totient is φ = 3320220.

The previous prime is 6640441. The next prime is 6640451. The reversal of 6640444 is 4440466.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6640441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830052 + ... + 830059.

Almost surely, 2^6640444 is an apocalyptic number.

It is an amenable number.

6640444 is a deficient number, since it is larger than the sum of its proper divisors (4980340).

6640444 is a wasteful number, since it uses less digits than its factorization.

6640444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1660115 (or 1660113 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 28.

The square root of 6640444 is about 2576.9058966132. The cubic root of 6640444 is about 187.9601167848.

The spelling of 6640444 in words is "six million, six hundred forty thousand, four hundred forty-four".