66220019549 has 2 divisors, whose sum is σ = 66220019550. Its totient is φ = 66220019548.

The previous prime is 66220019431. The next prime is 66220019597. The reversal of 66220019549 is 94591002266.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59125326649 + 7094692900 = 243157^2 + 84230^2 .

It is a cyclic number.

It is not a de Polignac number, because 66220019549 - 2²⁸ = 65951584093 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66220019149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33110009774 + 33110009775.

It is an arithmetic number, because the mean of its divisors is an integer number (33110009775).

Almost surely, 2^66220019549 is an apocalyptic number.

It is an amenable number.

66220019549 is a deficient number, since it is larger than the sum of its proper divisors (1).

66220019549 is an equidigital number, since it uses as much as digits as its factorization.

66220019549 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 233280, while the sum is 44.

The spelling of 66220019549 in words is "sixty-six billion, two hundred twenty million, nineteen thousand, five hundred forty-nine".