6544639 has 2 divisors, whose sum is σ = 6544640. Its totient is φ = 6544638.

The previous prime is 6544631. The next prime is 6544649. The reversal of 6544639 is 9364456.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6544639 - 2³ = 6544631 is a prime.

It is a Chen prime.

It is a d-powerful number, because it can be written as 6 + 5³ + 4⁷ + 4⁸ + 6⁸ + 3 + 9⁷ .

It is a junction number, because it is equal to n+sod(n) for n = 6544598 and 6544607.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6544631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3272319 + 3272320.

It is an arithmetic number, because the mean of its divisors is an integer number (3272320).

Almost surely, 2^6544639 is an apocalyptic number.

6544639 is a deficient number, since it is larger than the sum of its proper divisors (1).

6544639 is an equidigital number, since it uses as much as digits as its factorization.

6544639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 77760, while the sum is 37.

The square root of 6544639 is about 2558.2492060001. The cubic root of 6544639 is about 187.0518029721.

The spelling of 6544639 in words is "six million, five hundred forty-four thousand, six hundred thirty-nine".