11311205665 has 32 divisors (see below), whose sum is σ = 14051729664. Its totient is φ = 8735247360.

The previous prime is 11311205641. The next prime is 11311205699. The reversal of 11311205665 is 56650211311.

It is a happy number.

It is not a de Polignac number, because 11311205665 - 2²¹ = 11309108513 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13676982 + ... + 13677808.

It is an arithmetic number, because the mean of its divisors is an integer number (439116552).

Almost surely, 2^11311205665 is an apocalyptic number.

It is an amenable number.

11311205665 is a deficient number, since it is larger than the sum of its proper divisors (2740523999).

11311205665 is a wasteful number, since it uses less digits than its factorization.

11311205665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1497.

The product of its (nonzero) digits is 5400, while the sum is 31.

Adding to 11311205665 its reverse (56650211311), we get a palindrome (67961416976).

The spelling of 11311205665 in words is "eleven billion, three hundred eleven million, two hundred five thousand, six hundred sixty-five".