11665961666 has 4 divisors (see below), whose sum is σ = 17498942502. Its totient is φ = 5832980832.

The previous prime is 11665961641. The next prime is 11665961683. The reversal of 11665961666 is 66616956611.

11665961666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in only one way, i.e., 9288911641 + 2377050025 = 96379^2 + 48755^2 .

It is a Curzon number.

It is an unprimeable number.

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, 2916490415 + ... + 2916490418.

Almost surely, 2^11665961666 is an apocalyptic number.

11665961666 is a deficient number, since it is larger than the sum of its proper divisors (5832980836).

11665961666 is an equidigital number, since it uses as much as digits as its factorization.

11665961666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5832980835.

The product of its digits is 2099520, while the sum is 53.

The spelling of 11665961666 in words is "eleven billion, six hundred sixty-five million, nine hundred sixty-one thousand, six hundred sixty-six".