666140213 has 2 divisors, whose sum is σ = 666140214. Its totient is φ = 666140212.

The previous prime is 666140203. The next prime is 666140227. The reversal of 666140213 is 312041666.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 430272049 + 235868164 = 20743^2 + 15358^2 .

It is a cyclic number.

It is not a de Polignac number, because 666140213 - 2¹⁸ = 665878069 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666140203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333070106 + 333070107.

It is an arithmetic number, because the mean of its divisors is an integer number (333070107).

Almost surely, 2^666140213 is an apocalyptic number.

It is an amenable number.

666140213 is a deficient number, since it is larger than the sum of its proper divisors (1).

666140213 is an equidigital number, since it uses as much as digits as its factorization.

666140213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 666140213 is about 25809.6922298581. The cubic root of 666140213 is about 873.3504543614.

Adding to 666140213 its reverse (312041666), we get a palindrome (978181879).

The spelling of 666140213 in words is "six hundred sixty-six million, one hundred forty thousand, two hundred thirteen".