66211592261 has 2 divisors, whose sum is σ = 66211592262. Its totient is φ = 66211592260.

The previous prime is 66211592257. The next prime is 66211592329. The reversal of 66211592261 is 16229511266.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 43110632161 + 23100960100 = 207631^2 + 151990^2 .

It is a cyclic number.

It is not a de Polignac number, because 66211592261 - 2² = 66211592257 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66211592201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33105796130 + 33105796131.

It is an arithmetic number, because the mean of its divisors is an integer number (33105796131).

Almost surely, 2^66211592261 is an apocalyptic number.

It is an amenable number.

66211592261 is a deficient number, since it is larger than the sum of its proper divisors (1).

66211592261 is an equidigital number, since it uses as much as digits as its factorization.

66211592261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 77760, while the sum is 41.

The spelling of 66211592261 in words is "sixty-six billion, two hundred eleven million, five hundred ninety-two thousand, two hundred sixty-one".