4891005664549 has 2 divisors, whose sum is σ = 4891005664550. Its totient is φ = 4891005664548.

The previous prime is 4891005664529. The next prime is 4891005664621. The reversal of 4891005664549 is 9454665001984.

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., 2681055836449 + 2209949828100 = 1637393^2 + 1486590^2 .

It is a cyclic number.

It is not a de Polignac number, because 4891005664549 - 2³⁷ = 4753566711077 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4891005664529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2445502832274 + 2445502832275.

It is an arithmetic number, because the mean of its divisors is an integer number (2445502832275).

Almost surely, 2^{4891005664549} is an apocalyptic number.

It is an amenable number.

4891005664549 is a deficient number, since it is larger than the sum of its proper divisors (1).

4891005664549 is an equidigital number, since it uses as much as digits as its factorization.

4891005664549 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 37324800, while the sum is 61.

The spelling of 4891005664549 in words is "four trillion, eight hundred ninety-one billion, five million, six hundred sixty-four thousand, five hundred forty-nine".