66564310121 has 2 divisors, whose sum is σ = 66564310122. Its totient is φ = 66564310120.

The previous prime is 66564310093. The next prime is 66564310147. The reversal of 66564310121 is 12101346566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41111617600 + 25452692521 = 202760^2 + 159539^2 .

It is a cyclic number.

It is not a de Polignac number, because 66564310121 - 2²⁶ = 66497201257 is a prime.

It is not a weakly prime, because it can be changed into another prime (66564310151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33282155060 + 33282155061.

It is an arithmetic number, because the mean of its divisors is an integer number (33282155061).

Almost surely, 2^66564310121 is an apocalyptic number.

It is an amenable number.

66564310121 is a deficient number, since it is larger than the sum of its proper divisors (1).

66564310121 is an equidigital number, since it uses as much as digits as its factorization.

66564310121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25920, while the sum is 35.

Adding to 66564310121 its reverse (12101346566), we get a palindrome (78665656687).

The spelling of 66564310121 in words is "sixty-six billion, five hundred sixty-four million, three hundred ten thousand, one hundred twenty-one".