66212213 has 2 divisors, whose sum is σ = 66212214. Its totient is φ = 66212212.

The previous prime is 66212189. The next prime is 66212227. The reversal of 66212213 is 31221266.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66210769 + 1444 = 8137^2 + 38^2 .

It is a cyclic number.

It is not a de Polignac number, because 66212213 - 2⁶ = 66212149 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66212273) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33106106 + 33106107.

It is an arithmetic number, because the mean of its divisors is an integer number (33106107).

Almost surely, 2^66212213 is an apocalyptic number.

It is an amenable number.

66212213 is a deficient number, since it is larger than the sum of its proper divisors (1).

66212213 is an equidigital number, since it uses as much as digits as its factorization.

66212213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 23.

The square root of 66212213 is about 8137.0887300066. The cubic root of 66212213 is about 404.5566718309.

Adding to 66212213 its reverse (31221266), we get a palindrome (97433479).

The spelling of 66212213 in words is "sixty-six million, two hundred twelve thousand, two hundred thirteen".