6661153647649 has 2 divisors, whose sum is σ = 6661153647650. Its totient is φ = 6661153647648.

The previous prime is 6661153647647. The next prime is 6661153647661. The reversal of 6661153647649 is 9467463511666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6352128837649 + 309024810000 = 2520343^2 + 555900^2 .

It is a cyclic number.

It is not a de Polignac number, because 6661153647649 - 2¹ = 6661153647647 is a prime.

Together with 6661153647647, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (6661153647647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3330576823824 + 3330576823825.

It is an arithmetic number, because the mean of its divisors is an integer number (3330576823825).

Almost surely, 2^{6661153647649} is an apocalyptic number.

It is an amenable number.

6661153647649 is a deficient number, since it is larger than the sum of its proper divisors (1).

6661153647649 is an equidigital number, since it uses as much as digits as its factorization.

6661153647649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 117573120, while the sum is 64.

The spelling of 6661153647649 in words is "six trillion, six hundred sixty-one billion, one hundred fifty-three million, six hundred forty-seven thousand, six hundred forty-nine".