665216411 has 4 divisors (see below), whose sum is σ = 665314872. Its totient is φ = 665117952.

The previous prime is 665216389. The next prime is 665216417. The reversal of 665216411 is 114612566.

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 665216411 - 2¹⁰ = 665215387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665216417) 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, 38285 + ... + 52878.

It is an arithmetic number, because the mean of its divisors is an integer number (166328718).

Almost surely, 2^665216411 is an apocalyptic number.

665216411 is a deficient number, since it is larger than the sum of its proper divisors (98461).

665216411 is an equidigital number, since it uses as much as digits as its factorization.

665216411 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98460.

The product of its digits is 8640, while the sum is 32.

The square root of 665216411 is about 25791.7896044458. The cubic root of 665216411 is about 872.9465473331.

Adding to 665216411 its reverse (114612566), we get a palindrome (779828977).

The spelling of 665216411 in words is "six hundred sixty-five million, two hundred sixteen thousand, four hundred eleven".