11553616661 has 2 divisors, whose sum is σ = 11553616662. Its totient is φ = 11553616660.

The previous prime is 11553616643. The next prime is 11553616693. The reversal of 11553616661 is 16661635511.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11300965636 + 252651025 = 106306^2 + 15895^2 .

It is a cyclic number.

It is not a de Polignac number, because 11553616661 - 2⁶ = 11553616597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11553616631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5776808330 + 5776808331.

It is an arithmetic number, because the mean of its divisors is an integer number (5776808331).

Almost surely, 2^11553616661 is an apocalyptic number.

It is an amenable number.

11553616661 is a deficient number, since it is larger than the sum of its proper divisors (1).

11553616661 is an equidigital number, since it uses as much as digits as its factorization.

11553616661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 97200, while the sum is 41.

The spelling of 11553616661 in words is "eleven billion, five hundred fifty-three million, six hundred sixteen thousand, six hundred sixty-one".