6644647 has 2 divisors, whose sum is σ = 6644648. Its totient is φ = 6644646.

The previous prime is 6644621. The next prime is 6644681. The reversal of 6644647 is 7464466.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6644647 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6644047) 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 as a sum of consecutive naturals, namely, 3322323 + 3322324.

It is an arithmetic number, because the mean of its divisors is an integer number (3322324).

Almost surely, 2^6644647 is an apocalyptic number.

6644647 is a deficient number, since it is larger than the sum of its proper divisors (1).

6644647 is an equidigital number, since it uses as much as digits as its factorization.

6644647 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96768, while the sum is 37.

The square root of 6644647 is about 2577.7212805111. The cubic root of 6644647 is about 187.9997642218. Note that the first 3 decimals are identical.

The spelling of 6644647 in words is "six million, six hundred forty-four thousand, six hundred forty-seven".