6640449 has 16 divisors (see below), whose sum is σ = 9246720. Its totient is φ = 4233600.

The previous prime is 6640441. The next prime is 6640451. The reversal of 6640449 is 9440466.

It is not a de Polignac number, because 6640449 - 2³ = 6640441 is a prime.

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 in 15 ways as a sum of consecutive naturals, for example, 10749 + ... + 11349.

It is an arithmetic number, because the mean of its divisors is an integer number (577920).

Almost surely, 2^6640449 is an apocalyptic number.

It is an amenable number.

6640449 is a deficient number, since it is larger than the sum of its proper divisors (2606271).

6640449 is a wasteful number, since it uses less digits than its factorization.

6640449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 760.

The product of its (nonzero) digits is 20736, while the sum is 33.

The square root of 6640449 is about 2576.9068667688. The cubic root of 6640449 is about 187.9601639604.

The spelling of 6640449 in words is "six million, six hundred forty thousand, four hundred forty-nine".