666786041 has 2 divisors, whose sum is σ = 666786042. Its totient is φ = 666786040.

The previous prime is 666786023. The next prime is 666786047. The reversal of 666786041 is 140687666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 589275625 + 77510416 = 24275^2 + 8804^2 .

It is a cyclic number.

It is not a de Polignac number, because 666786041 - 2¹⁴ = 666769657 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 666785983 and 666786001.

It is not a weakly prime, because it can be changed into another prime (666786047) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333393020 + 333393021.

It is an arithmetic number, because the mean of its divisors is an integer number (333393021).

Almost surely, 2^666786041 is an apocalyptic number.

It is an amenable number.

666786041 is a deficient number, since it is larger than the sum of its proper divisors (1).

666786041 is an equidigital number, since it uses as much as digits as its factorization.

666786041 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 290304, while the sum is 44.

The square root of 666786041 is about 25822.2005452672. The cubic root of 666786041 is about 873.6326031672.

The spelling of 666786041 in words is "six hundred sixty-six million, seven hundred eighty-six thousand, forty-one".