6561697219547 has 2 divisors, whose sum is σ = 6561697219548. Its totient is φ = 6561697219546.

The previous prime is 6561697219537. The next prime is 6561697219669. The reversal of 6561697219547 is 7459127961656.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6561697219547 - 2⁸ = 6561697219291 is a prime.

It is not a weakly prime, because it can be changed into another prime (6561697219507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3280848609773 + 3280848609774.

It is an arithmetic number, because the mean of its divisors is an integer number (3280848609774).

Almost surely, 2^{6561697219547} is an apocalyptic number.

6561697219547 is a deficient number, since it is larger than the sum of its proper divisors (1).

6561697219547 is an equidigital number, since it uses as much as digits as its factorization.

6561697219547 is an evil number, because the sum of its binary digits is even.

The product of its digits is 171460800, while the sum is 68.

The spelling of 6561697219547 in words is "six trillion, five hundred sixty-one billion, six hundred ninety-seven million, two hundred nineteen thousand, five hundred forty-seven".