66090366721 has 2 divisors, whose sum is σ = 66090366722. Its totient is φ = 66090366720.

The previous prime is 66090366679. The next prime is 66090366737. The reversal of 66090366721 is 12766309066.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49024602225 + 17065764496 = 221415^2 + 130636^2 .

It is a cyclic number.

It is not a de Polignac number, because 66090366721 - 2¹⁷ = 66090235649 is a prime.

It is not a weakly prime, because it can be changed into another prime (66090366781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33045183360 + 33045183361.

It is an arithmetic number, because the mean of its divisors is an integer number (33045183361).

Almost surely, 2^66090366721 is an apocalyptic number.

It is an amenable number.

66090366721 is a deficient number, since it is larger than the sum of its proper divisors (1).

66090366721 is an equidigital number, since it uses as much as digits as its factorization.

66090366721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 489888, while the sum is 46.

The spelling of 66090366721 in words is "sixty-six billion, ninety million, three hundred sixty-six thousand, seven hundred twenty-one".