11571711665 has 8 divisors (see below), whose sum is σ = 13887437928. Its totient is φ = 9256446720.

The previous prime is 11571711649. The next prime is 11571711667. The reversal of 11571711665 is 56611717511.

It can be written as a sum of positive squares in 4 ways, for example, as 89946256 + 11481765409 = 9484^2 + 107153^2 .

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

It is not a de Polignac number, because 11571711665 - 2⁴ = 11571711649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11571711667) 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, 57506 + ... + 162635.

It is an arithmetic number, because the mean of its divisors is an integer number (1735929741).

Almost surely, 2^11571711665 is an apocalyptic number.

It is an amenable number.

11571711665 is a deficient number, since it is larger than the sum of its proper divisors (2315726263).

11571711665 is a wasteful number, since it uses less digits than its factorization.

11571711665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230659.

The product of its digits is 44100, while the sum is 41.

The spelling of 11571711665 in words is "eleven billion, five hundred seventy-one million, seven hundred eleven thousand, six hundred sixty-five".