12135815280 has 400 divisors, whose sum is σ = 44660906400. Its totient is φ = 3045703680.

The previous prime is 12135815269. The next prime is 12135815297. The reversal of 12135815280 is 8251853121.

12135815280 is a `hidden beast` number, since 1 + 21 + 3 + 581 + 52 + 8 + 0 = 666.

12135815280 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 (36).

It is a congruent number.

It is an unprimeable number.

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 79 ways as a sum of consecutive naturals, for example, 29671716 + ... + 29672124.

It is an arithmetic number, because the mean of its divisors is an integer number (111652266).

Almost surely, 2^12135815280 is an apocalyptic number.

12135815280 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 12135815280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22330453200).

12135815280 is an abundant number, since it is smaller than the sum of its proper divisors (32525091120).

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

12135815280 is a wasteful number, since it uses less digits than its factorization.

12135815280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 694 (or 679 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 36.

The spelling of 12135815280 in words is "twelve billion, one hundred thirty-five million, eight hundred fifteen thousand, two hundred eighty".