11600216561 has 2 divisors, whose sum is σ = 11600216562. Its totient is φ = 11600216560.

The previous prime is 11600216527. The next prime is 11600216567. The reversal of 11600216561 is 16561200611.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6090865936 + 5509350625 = 78044^2 + 74225^2 .

It is an emirp because it is prime and its reverse (16561200611) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11600216561 - 2²⁶ = 11533107697 is a prime.

It is not a weakly prime, because it can be changed into another prime (11600216567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5800108280 + 5800108281.

It is an arithmetic number, because the mean of its divisors is an integer number (5800108281).

Almost surely, 2^11600216561 is an apocalyptic number.

It is an amenable number.

11600216561 is a deficient number, since it is larger than the sum of its proper divisors (1).

11600216561 is an equidigital number, since it uses as much as digits as its factorization.

11600216561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 29.

The spelling of 11600216561 in words is "eleven billion, six hundred million, two hundred sixteen thousand, five hundred sixty-one".