6544403620649 has 2 divisors, whose sum is σ = 6544403620650. Its totient is φ = 6544403620648.

The previous prime is 6544403620631. The next prime is 6544403620673. The reversal of 6544403620649 is 9460263044456.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6281740195600 + 262663425049 = 2506340^2 + 512507^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6544403620649 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6544403620649.

It is not a weakly prime, because it can be changed into another prime (6544403623649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3272201810324 + 3272201810325.

It is an arithmetic number, because the mean of its divisors is an integer number (3272201810325).

Almost surely, 2^{6544403620649} is an apocalyptic number.

It is an amenable number.

6544403620649 is a deficient number, since it is larger than the sum of its proper divisors (1).

6544403620649 is an equidigital number, since it uses as much as digits as its factorization.

6544403620649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14929920, while the sum is 53.

The spelling of 6544403620649 in words is "six trillion, five hundred forty-four billion, four hundred three million, six hundred twenty thousand, six hundred forty-nine".