12109721136 has 80 divisors (see below), whose sum is σ = 32979853440. Its totient is φ = 3818327040.

The previous prime is 12109721123. The next prime is 12109721137. The reversal of 12109721136 is 63112790121.

12109721136 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 12109721097 and 12109721106.

It is not an unprimeable number, because it can be changed into a prime (12109721137) 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 15 ways as a sum of consecutive naturals, for example, 613176 + ... + 632616.

It is an arithmetic number, because the mean of its divisors is an integer number (412248168).

Almost surely, 2^12109721136 is an apocalyptic number.

12109721136 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 12109721136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16489926720).

12109721136 is an abundant number, since it is smaller than the sum of its proper divisors (20870132304).

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

12109721136 is a wasteful number, since it uses less digits than its factorization.

12109721136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20154 (or 20148 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 33.

The spelling of 12109721136 in words is "twelve billion, one hundred nine million, seven hundred twenty-one thousand, one hundred thirty-six".