11661066556617 has 4 divisors (see below), whose sum is σ = 15548088742160. Its totient is φ = 7774044371076.

The previous prime is 11661066556609. The next prime is 11661066556631. The reversal of 11661066556617 is 71665566016611.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 11661066556617 - 2³ = 11661066556609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11661066556637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1943511092767 + ... + 1943511092772.

It is an arithmetic number, because the mean of its divisors is an integer number (3887022185540).

Almost surely, 2^{11661066556617} is an apocalyptic number.

It is an amenable number.

11661066556617 is a deficient number, since it is larger than the sum of its proper divisors (3887022185543).

11661066556617 is an equidigital number, since it uses as much as digits as its factorization.

11661066556617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3887022185542.

The product of its (nonzero) digits is 8164800, while the sum is 57.

The spelling of 11661066556617 in words is "eleven trillion, six hundred sixty-one billion, sixty-six million, five hundred fifty-six thousand, six hundred seventeen".