11001561161561 has 8 divisors (see below), whose sum is σ = 11893579634880. Its totient is φ = 10140841582128.

The previous prime is 11001561161497. The next prime is 11001561161567. The reversal of 11001561161561 is 16516116510011.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 11001561161561 - 2⁶ = 11001561161497 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (11001561161567) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7824722741 + ... + 7824724146.

It is an arithmetic number, because the mean of its divisors is an integer number (1486697454360).

Almost surely, 2^{11001561161561} is an apocalyptic number.

It is an amenable number.

11001561161561 is a deficient number, since it is larger than the sum of its proper divisors (892018473319).

11001561161561 is a wasteful number, since it uses less digits than its factorization.

11001561161561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15649446943.

The product of its (nonzero) digits is 5400, while the sum is 35.

Adding to 11001561161561 its reverse (16516116510011), we get a palindrome (27517677671572).

The spelling of 11001561161561 in words is "eleven trillion, one billion, five hundred sixty-one million, one hundred sixty-one thousand, five hundred sixty-one".