11506561065 has 12 divisors (see below), whose sum is σ = 19944705924. Its totient is φ = 6136832544.

The previous prime is 11506560977. The next prime is 11506561091. The reversal of 11506561065 is 56016560511.

It can be written as a sum of positive squares in 2 ways, for example, as 5193940761 + 6312620304 = 72069^2 + 79452^2 .

It is not a de Polignac number, because 11506561065 - 2⁷ = 11506560937 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 127850634 + ... + 127850723.

It is an arithmetic number, because the mean of its divisors is an integer number (1662058827).

Almost surely, 2^11506561065 is an apocalyptic number.

11506561065 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

11506561065 is a deficient number, since it is larger than the sum of its proper divisors (8438144859).

11506561065 is a wasteful number, since it uses less digits than its factorization.

11506561065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255701368 (or 255701365 counting only the distinct ones).

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

The spelling of 11506561065 in words is "eleven billion, five hundred six million, five hundred sixty-one thousand, sixty-five".