11521513665 has 48 divisors (see below), whose sum is σ = 20158235136. Its totient is φ = 6087312000.

The previous prime is 11521513639. The next prime is 11521513699. The reversal of 11521513665 is 56631512511.

11521513665 is a `hidden beast` number, since 115 + 21 + 513 + 6 + 6 + 5 = 666.

11521513665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 11521513665 - 2¹⁰ = 11521512641 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2695480 + ... + 2699750.

It is an arithmetic number, because the mean of its divisors is an integer number (419963232).

Almost surely, 2^11521513665 is an apocalyptic number.

11521513665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

11521513665 is a deficient number, since it is larger than the sum of its proper divisors (8636721471).

11521513665 is a wasteful number, since it uses less digits than its factorization.

11521513665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4830 (or 4827 counting only the distinct ones).

The product of its digits is 27000, while the sum is 36.

The spelling of 11521513665 in words is "eleven billion, five hundred twenty-one million, five hundred thirteen thousand, six hundred sixty-five".