66222209 has 2 divisors, whose sum is σ = 66222210. Its totient is φ = 66222208.

The previous prime is 66222199. The next prime is 66222227. The reversal of 66222209 is 90222266.

66222209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39337984 + 26884225 = 6272^2 + 5185^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66222209 is a prime.

It is not a weakly prime, because it can be changed into another prime (66222269) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33111104 + 33111105.

It is an arithmetic number, because the mean of its divisors is an integer number (33111105).

Almost surely, 2^66222209 is an apocalyptic number.

It is an amenable number.

66222209 is a deficient number, since it is larger than the sum of its proper divisors (1).

66222209 is an equidigital number, since it uses as much as digits as its factorization.

66222209 is an odious number, because the sum of its binary digits is odd.

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

The square root of 66222209 is about 8137.7029314174. The cubic root of 66222209 is about 404.5770293290.

The spelling of 66222209 in words is "sixty-six million, two hundred twenty-two thousand, two hundred nine".