6645526666553 has 2 divisors, whose sum is σ = 6645526666554. Its totient is φ = 6645526666552.

The previous prime is 6645526666547. The next prime is 6645526666561. The reversal of 6645526666553 is 3556666255466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6578568376384 + 66958290169 = 2564872^2 + 258763^2 .

It is a cyclic number.

It is not a de Polignac number, because 6645526666553 - 2⁶ = 6645526666489 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6645526666553.

It is not a weakly prime, because it can be changed into another prime (6645526666573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3322763333276 + 3322763333277.

It is an arithmetic number, because the mean of its divisors is an integer number (3322763333277).

Almost surely, 2^{6645526666553} is an apocalyptic number.

It is an amenable number.

6645526666553 is a deficient number, since it is larger than the sum of its proper divisors (1).

6645526666553 is an equidigital number, since it uses as much as digits as its factorization.

6645526666553 is an evil number, because the sum of its binary digits is even.

The product of its digits is 699840000, while the sum is 65.

The spelling of 6645526666553 in words is "six trillion, six hundred forty-five billion, five hundred twenty-six million, six hundred sixty-six thousand, five hundred fifty-three".