11971841520 has 80 divisors (see below), whose sum is σ = 37176370560. Its totient is φ = 3187014912.

The previous prime is 11971841449. The next prime is 11971841533. The reversal of 11971841520 is 2514817911.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 98391 + ... + 183369.

It is an arithmetic number, because the mean of its divisors is an integer number (464704632).

Almost surely, 2^11971841520 is an apocalyptic number.

11971841520 is a gapful number since it is divisible by the number (10) 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 11971841520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18588185280).

11971841520 is an abundant number, since it is smaller than the sum of its proper divisors (25204529040).

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

11971841520 is a wasteful number, since it uses less digits than its factorization.

11971841520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85582 (or 85576 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 39.

The spelling of 11971841520 in words is "eleven billion, nine hundred seventy-one million, eight hundred forty-one thousand, five hundred twenty".