665542211 has 2 divisors, whose sum is σ = 665542212. Its totient is φ = 665542210.

The previous prime is 665542201. The next prime is 665542219. The reversal of 665542211 is 112245566.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 665542211 - 2¹⁸ = 665280067 is a prime.

It is a Sophie Germain prime.

It is a nialpdrome in base 10.

It is not a weakly prime, because it can be changed into another prime (665542219) 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, 332771105 + 332771106.

It is an arithmetic number, because the mean of its divisors is an integer number (332771106).

Almost surely, 2^665542211 is an apocalyptic number.

665542211 is a deficient number, since it is larger than the sum of its proper divisors (1).

665542211 is an equidigital number, since it uses as much as digits as its factorization.

665542211 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14400, while the sum is 32.

The square root of 665542211 is about 25798.1047947325. The cubic root of 665542211 is about 873.0890370864.

Adding to 665542211 its reverse (112245566), we get a palindrome (777787777).

The spelling of 665542211 in words is "six hundred sixty-five million, five hundred forty-two thousand, two hundred eleven".