12665239920 has 160 divisors (see below), whose sum is σ = 43887191040. Its totient is φ = 3357077760.

The previous prime is 12665239907. The next prime is 12665239927. The reversal of 12665239920 is 2993256621.

12665239920 is a `hidden beast` number, since 12 + 6 + 6 + 523 + 99 + 20 = 666.

12665239920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12665239927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 343165 + ... + 378275.

It is an arithmetic number, because the mean of its divisors is an integer number (274294944).

Almost surely, 2^12665239920 is an apocalyptic number.

12665239920 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 12665239920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21943595520).

12665239920 is an abundant number, since it is smaller than the sum of its proper divisors (31221951120).

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

12665239920 is a wasteful number, since it uses less digits than its factorization.

12665239920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35300 (or 35288 counting only the distinct ones).

The product of its (nonzero) digits is 349920, while the sum is 45.

The spelling of 12665239920 in words is "twelve billion, six hundred sixty-five million, two hundred thirty-nine thousand, nine hundred twenty".