66212735609 has 2 divisors, whose sum is σ = 66212735610. Its totient is φ = 66212735608.

The previous prime is 66212735597. The next prime is 66212735653. The reversal of 66212735609 is 90653721266.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 44641351225 + 21571384384 = 211285^2 + 146872^2 .

It is a cyclic number.

It is not a de Polignac number, because 66212735609 - 2²⁰ = 66211687033 is a prime.

It is not a weakly prime, because it can be changed into another prime (66212735909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33106367804 + 33106367805.

It is an arithmetic number, because the mean of its divisors is an integer number (33106367805).

Almost surely, 2^66212735609 is an apocalyptic number.

It is an amenable number.

66212735609 is a deficient number, since it is larger than the sum of its proper divisors (1).

66212735609 is an equidigital number, since it uses as much as digits as its factorization.

66212735609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 816480, while the sum is 47.

The spelling of 66212735609 in words is "sixty-six billion, two hundred twelve million, seven hundred thirty-five thousand, six hundred nine".