11809681917 has 12 divisors (see below), whose sum is σ = 17307853920. Its totient is φ = 7157382760.

The previous prime is 11809681879. The next prime is 11809681927. The reversal of 11809681917 is 71918690811.

It is a happy number.

It is not a de Polignac number, because 11809681917 - 2¹⁰ = 11809680893 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 11809681917.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11809681927) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16266417 + ... + 16267142.

It is an arithmetic number, because the mean of its divisors is an integer number (1442321160).

Almost surely, 2^11809681917 is an apocalyptic number.

It is an amenable number.

11809681917 is a deficient number, since it is larger than the sum of its proper divisors (5498172003).

11809681917 is a wasteful number, since it uses less digits than its factorization.

11809681917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32533584 (or 32533573 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 51.

The spelling of 11809681917 in words is "eleven billion, eight hundred nine million, six hundred eighty-one thousand, nine hundred seventeen".