665843550211 has 4 divisors (see below), whose sum is σ = 760964057392. Its totient is φ = 570723043032.

The previous prime is 665843550187. The next prime is 665843550223. The reversal of 665843550211 is 112055348566.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 665843550211 - 2⁷ = 665843550083 is a prime.

It is a super-3 number, since 3×665843550211³ (a number of 36 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (665843550241) 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 in 3 ways as a sum of consecutive naturals, for example, 47560253580 + ... + 47560253593.

It is an arithmetic number, because the mean of its divisors is an integer number (190241014348).

Almost surely, 2^665843550211 is an apocalyptic number.

665843550211 is a deficient number, since it is larger than the sum of its proper divisors (95120507181).

665843550211 is an equidigital number, since it uses as much as digits as its factorization.

665843550211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95120507180.

The product of its (nonzero) digits is 864000, while the sum is 46.

Adding to 665843550211 its reverse (112055348566), we get a palindrome (777898898777).

The spelling of 665843550211 in words is "six hundred sixty-five billion, eight hundred forty-three million, five hundred fifty thousand, two hundred eleven".