6640049 has 4 divisors (see below), whose sum is σ = 7150836. Its totient is φ = 6129264.

The previous prime is 6640027. The next prime is 6640061. The reversal of 6640049 is 9400466.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3150625 + 3489424 = 1775^2 + 1868^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6640049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6640009) 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, 255374 + ... + 255399.

It is an arithmetic number, because the mean of its divisors is an integer number (1787709).

Almost surely, 2^6640049 is an apocalyptic number.

It is an amenable number.

6640049 is a deficient number, since it is larger than the sum of its proper divisors (510787).

6640049 is a wasteful number, since it uses less digits than its factorization.

6640049 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 510786.

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 6640049 is about 2576.8292531714. The cubic root of 6640049 is about 187.9563898393.

The spelling of 6640049 in words is "six million, six hundred forty thousand, forty-nine".