11665505616 has 80 divisors (see below), whose sum is σ = 30766780800. Its totient is φ = 3807838720.

The previous prime is 11665505611. The next prime is 11665505627. The reversal of 11665505616 is 61650556611.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11665505611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 496306 + ... + 519278.

It is an arithmetic number, because the mean of its divisors is an integer number (384584760).

Almost surely, 2^11665505616 is an apocalyptic number.

11665505616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 11665505616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15383390400).

11665505616 is an abundant number, since it is smaller than the sum of its proper divisors (19101275184).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

11665505616 is a wasteful number, since it uses less digits than its factorization.

11665505616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23204 (or 23198 counting only the distinct ones).

The product of its (nonzero) digits is 162000, while the sum is 42.

The spelling of 11665505616 in words is "eleven billion, six hundred sixty-five million, five hundred five thousand, six hundred sixteen".