12665881536 has 448 divisors, whose sum is σ = 44702699520. Its totient is φ = 3065610240.

The previous prime is 12665881531. The next prime is 12665881567. The reversal of 12665881536 is 63518856621.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (448).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12665881531) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 18819696 + ... + 18820368.

Almost surely, 2^12665881536 is an apocalyptic number.

12665881536 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 12665881536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22351349760).

12665881536 is an abundant number, since it is smaller than the sum of its proper divisors (32036817984).

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

12665881536 is a wasteful number, since it uses less digits than its factorization.

12665881536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 792 (or 782 counting only the distinct ones).

The product of its digits is 2073600, while the sum is 51.

The spelling of 12665881536 in words is "twelve billion, six hundred sixty-five million, eight hundred eighty-one thousand, five hundred thirty-six".