866618213 has 2 divisors, whose sum is σ = 866618214. Its totient is φ = 866618212.

The previous prime is 866618171. The next prime is 866618227. The reversal of 866618213 is 312816668.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 730242529 + 136375684 = 27023^2 + 11678^2 .

It is a cyclic number.

It is not a de Polignac number, because 866618213 - 2¹⁸ = 866356069 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866618243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433309106 + 433309107.

It is an arithmetic number, because the mean of its divisors is an integer number (433309107).

Almost surely, 2^866618213 is an apocalyptic number.

It is an amenable number.

866618213 is a deficient number, since it is larger than the sum of its proper divisors (1).

866618213 is an equidigital number, since it uses as much as digits as its factorization.

866618213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 82944, while the sum is 41.

The square root of 866618213 is about 29438.3799316471. The cubic root of 866618213 is about 953.4017337130.

The spelling of 866618213 in words is "eight hundred sixty-six million, six hundred eighteen thousand, two hundred thirteen".