12138281568 has 672 divisors, whose sum is σ = 43959585600. Its totient is φ = 3292047360.

The previous prime is 12138281563. The next prime is 12138281581. The reversal of 12138281568 is 86518283121.

12138281568 is a `hidden beast` number, since 1 + 2 + 1 + 3 + 8 + 2 + 81 + 568 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

Its product of digits (184320) is a multiple of the sum of its prime divisors (90).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12138281563) by changing a digit.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 296055628 + ... + 296055668.

It is an arithmetic number, because the mean of its divisors is an integer number (65416050).

Almost surely, 2^12138281568 is an apocalyptic number.

12138281568 is a gapful number since it is divisible by the number (18) 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 12138281568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21979792800).

12138281568 is an abundant number, since it is smaller than the sum of its proper divisors (31821304032).

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

12138281568 is an frugal number, since it uses more digits than its factorization.

12138281568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127 (or 90 counting only the distinct ones).

The product of its digits is 184320, while the sum is 45.

The spelling of 12138281568 in words is "twelve billion, one hundred thirty-eight million, two hundred eighty-one thousand, five hundred sixty-eight".