11561016511 has 24 divisors (see below), whose sum is σ = 13014473472. Its totient is φ = 10258248000.

The previous prime is 11561016491. The next prime is 11561016517.

11561016511 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 11561016511 - 2¹¹ = 11561014463 is a prime.

It is a super-2 number, since 2×11561016511² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 11561016511.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11561016517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1258786 + ... + 1267936.

It is an arithmetic number, because the mean of its divisors is an integer number (542269728).

Almost surely, 2^11561016511 is an apocalyptic number.

11561016511 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

11561016511 is a deficient number, since it is larger than the sum of its proper divisors (1453456961).

11561016511 is a wasteful number, since it uses less digits than its factorization.

11561016511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9423 (or 9412 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 28.

The spelling of 11561016511 in words is "eleven billion, five hundred sixty-one million, sixteen thousand, five hundred eleven".