66065917 has 2 divisors, whose sum is σ = 66065918. Its totient is φ = 66065916.

The previous prime is 66065911. The next prime is 66065941. The reversal of 66065917 is 71956066.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 58079641 + 7986276 = 7621^2 + 2826^2 .

It is a cyclic number.

It is not a de Polignac number, because 66065917 - 2¹⁹ = 65541629 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66065917.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66065911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33032958 + 33032959.

It is an arithmetic number, because the mean of its divisors is an integer number (33032959).

Almost surely, 2^66065917 is an apocalyptic number.

It is an amenable number.

66065917 is a deficient number, since it is larger than the sum of its proper divisors (1).

66065917 is an equidigital number, since it uses as much as digits as its factorization.

66065917 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 68040, while the sum is 40.

The square root of 66065917 is about 8128.0943030947. The cubic root of 66065917 is about 404.2584958924.

The spelling of 66065917 in words is "sixty-six million, sixty-five thousand, nine hundred seventeen".