66566612417 has 2 divisors, whose sum is σ = 66566612418. Its totient is φ = 66566612416.

The previous prime is 66566612389. The next prime is 66566612429. The reversal of 66566612417 is 71421666566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 52698252721 + 13868359696 = 229561^2 + 117764^2 .

It is a cyclic number.

It is not a de Polignac number, because 66566612417 - 2²⁸ = 66298176961 is a prime.

It is a super-2 number, since 2×66566612417² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66566612447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33283306208 + 33283306209.

It is an arithmetic number, because the mean of its divisors is an integer number (33283306209).

Almost surely, 2^66566612417 is an apocalyptic number.

It is an amenable number.

66566612417 is a deficient number, since it is larger than the sum of its proper divisors (1).

66566612417 is an equidigital number, since it uses as much as digits as its factorization.

66566612417 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2177280, while the sum is 50.

The spelling of 66566612417 in words is "sixty-six billion, five hundred sixty-six million, six hundred twelve thousand, four hundred seventeen".