11538611665 has 16 divisors (see below), whose sum is σ = 15854663808. Its totient is φ = 7897049856.

The previous prime is 11538611663. The next prime is 11538611681. The reversal of 11538611665 is 56611683511.

It is a cyclic number.

It is not a de Polignac number, because 11538611665 - 2¹ = 11538611663 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11538611663) 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 15 ways as a sum of consecutive naturals, for example, 296872 + ... + 333481.

It is an arithmetic number, because the mean of its divisors is an integer number (990916488).

Almost surely, 2^11538611665 is an apocalyptic number.

It is an amenable number.

11538611665 is a deficient number, since it is larger than the sum of its proper divisors (4316052143).

11538611665 is an equidigital number, since it uses as much as digits as its factorization.

11538611665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 630888.

The product of its digits is 129600, while the sum is 43.

The spelling of 11538611665 in words is "eleven billion, five hundred thirty-eight million, six hundred eleven thousand, six hundred sixty-five".